CHAMBER FOR DEGASSING SUBSTRATES

Abstract

A heater and/or cooler chamber includes a heat storage block or chunk. In the block a multitude of parallel, stacked slit pockets each dimensioned to accommodate a single plate shaped workpiece. Workpiece handling openings of the slit pockets are freed and respectively covered by a door arrangement. The slit pockets are tailored to snuggly surround the plate shaped workpieces therein so as to establish an efficient heat transfer between the heat storage block or chunk and the workpieces to be cooled or heated.

Claims

1. A method of treating workpieces or of manufacturing treated workpieces thereby providing: a number of slit pockets each dimensioned to accommodate a single of said workpieces therein, and comprising first loading workpieces subsequently in time and with a time lag between subsequent first loadings into first slit pockets of said number of slit pockets and performing treatment of said workpieces loaded subsequently in time in said first slit pockets, thereby selecting said first slit pockets by skipping second slit pockets between first slit pockets; and, thereafter, second loading workpieces subsequently in time and with a time lag between subsequent second loadings into second slit pockets of said number of slit pockets having been skipped by said first loading and performing treatment of said workpieces loaded subsequently in time in said second slit pockets; unloading subsequently in time and with a time lag between subsequent unloadings, workpieces from said first and from said second slit pockets, treatment of said workpieces being unloaded having been completed.

2. The method of claim 1, comprising said unloading by unloading a workpiece having been completely treated from respective slit pockets of said first and said second slit pockets and performing, directly succeedingly to said unloading, said first and second loadings respectively into said slit pockets having been freed by said unloading.

3. The method of claim 1, comprising selecting said time lag between subsequent first loadings, said time lag between subsequent second loadings and said time lag between subsequent unloadings are equal.

4. The method of claim 2, wherein said time lag between subsequent first loadings, said time lag between subsequent second loadings and said time lag between subsequent unloadings are equal.

5. The method of claim 3, wherein said time lag is selected in dependency of a workpiece throughput to be achieved.

6. The method of claim 4, wherein said time lag is selected in dependency of a workpiece throughput to be achieved.

7. The method of claim 3, comprising selecting a treatment time span for complete treatment of said workpieces and determining said number in dependency of the extent of said time lags and of said selected treatment time span for complete treatment.

8. The method of claim 4, comprising selecting a treatment time span for complete treatment of said workpieces and determining said number in dependency of the extent of said time lags and of said selected treatment time span for complete treatment.

9. The method of claim 5, comprising selecting a treatment time span for complete treatment of said workpieces and determining said number in dependency of the extent of said time lags and of said selected treatment time span for complete treatment.

10. The method of claim 6, comprising selecting a treatment time span for complete treatment of said workpieces and determining said number in dependency of the extent of said time lags and of said selected treatment time span for complete treatment.

11. The method of claim 1, wherein said treatment is a thermal treatment.

12. The method of claim 11 comprising minimizing heat exchange between workpieces just having been loaded and workpieces just being completely treated by said first and second loadings.

13. The method of claim 2 comprising minimizing the extent of handling paths for loading and unloading of workpieces by said unloading a workpiece having been completely treated from respective slit pockets of said first and said second slit pockets and by performing, directly succeedingly to said unloading, said first and second loadings respectively into said slit pockets having been freed by said unloading.

14. The method of claim 11 comprising minimizing the extent of handling paths for loading and unloading of workpieces by unloading a workpiece having been completely treated from respective slit pockets of said first and said second slit pockets and by performing, directly succeedingly to said unloading, said first and second loadings respectively into said slit pockets having been freed by said unloading.

15. The method of claim 1, wherein said number of slit pockets are arranged to form a stack of slit pockets.

16. The method of claim 11 wherein said number of slit pockets are arranged to form a stack of slit pockets.

17. The method of claim 1 comprising providing more of said slit pockets than said number of slit pockets.

18. The method of claim 3, 11, 14 or 16 comprising: selecting a treatment time span for completing treatment of said workpieces and selecting said time lags in dependency of a desired throughput of completely treated workpieces, and further selecting said number to be at least equal to a quotient of said treatment time span and of said time lags, rounded to the next higher integer.

19. A method of treating workpieces or of manufacturing treated workpieces thereby providing: a number of slit pockets each dimensioned to accommodate a single of said workpieces therein, and comprising first loading workpieces subsequently in time and with a time lag between subsequent first loadings into first slit pockets of said number of slit pockets and performing a heat treatment of said workpieces loaded subsequently in time in said first slit pockets, thereby selecting said first slit pockets by skipping second slit pockets between first slit pockets; and, thereafter, second loading workpieces subsequently in time and with a time lag between subsequent second loadings into second slit pockets of said number of slit pockets having been skipped by said first loading and performing heat treatment of said workpieces loaded subsequently in time in said second slit pockets; unloading subsequently in time and with a time lag between subsequent unloadings, workpieces from said first and from said second slit pockets, heat treatment of said workpieces being unloaded having been completed, and further comprising said unloading by unloading a workpiece having been completely treated from respective slit pockets of said first and said second slit pockets and performing, directly succeedingly to said unloading, said first and second loadings respectively into said slit pockets having been freed by said unloading and selecting said time lag between subsequent first loadings, said time lag between subsequent second loadings and said time lag between subsequent unloadings to be equal.

Description

[0119] The invention and different aspects thereof shall now further be exemplified with the help of figures.

[0120] The Figures show:

[0121] FIG. 1 schematically and in a perspective view a block of a chamber according to the present invention, shown most generically, with a slit-pocket, to explain the definition of the term “slit-pocket plane”;

[0122] FIG. 2 still in a schematic, simplified representation a cross-section through a block of the chamber according to the invention along the slit-pockets.

[0123] FIG. 3 in a representation in analogy to that of FIG. 2, a first embodiment of realizing a door arrangement as used in the chamber according to the present invention.

[0124] FIG. 4a in a representation in analogy to that of FIG. 3 a further embodiment of realizing the door arrangement.

[0125] FIG. 4b still in a representation in analogy to the representations of the FIG. 3 or 4a a further embodiment of realizing the door arrangement.

[0126] FIG. 5 still in a representation in analogy to that of the FIGS. 3 and 4a, 4b a further, today practiced embodiment of the door arrangement and as provided in the chamber according to the invention.

[0127] FIG. 6a a simplified cross-sectional view along the dash-dotted lines A-A in FIG. 2 and through a part of a slit-pocket.

[0128] FIG. 6b in a representation in analogy to that of FIG. 6a a further embodiment of possibly structuring the bottom section of a slit-pocket in the chamber according the present invention.

[0129] FIG. 7 in perspective view still schematically and simplified an embodiment of the chamber according to the invention.

[0130] In FIG. 8 shows schematically and simplified a cross-section through an embodiment of a chamber according to the invention with an isolating housing surrounding the block of the chamber.

[0131] FIG. 9a shows a top-view on a slit-pocket of an embodiment of the chamber according to the invention with a transfer arm of the handling robot.

[0132] FIG. 9b shows a cross-section through the slit-pocket as of FIG. 9a.

[0133] FIG. 10 shows schematically and simplified a cross-section through an embodiment of the chamber according to the invention, the door arrangement comprising a door plate with a door-workpiece-handling opening—DWHO—in closed or covering position.

[0134] FIG. 11 shows in a representation in analogy to that of FIG. 10 the cross-section through an embodiment of the chamber according to the invention and according to the embodiment of FIG. 10 whereby the door plate frees the lowest slit-pocket (left-hand representation) and the uppermost slit-pocket (right-.hand representation).

[0135] FIG. 12 shows in a representation in analogy to those of FIGS. 10 and 11 a cross-section through an embodiment of the chamber according to the invention, the door plate of the door arrangement covering all workpiece-handling openings of the slit-pockets in a position where the DWHO is in an intermediate position between two neighboring slit-pockets.

[0136] FIG. 13 shows in a representation in analogy to those of the FIGS. 10 to 12 a part of an embodiment of a chamber according to the invention wherein the door arrangement is implemented by two independently driven door plates.

[0137] FIG. 14 shows in a representation in analogy to those of the FIGS. 10 to 13 a cross-section through an embodiment of the chamber according to the invention wherein the door arrangement is operated by a driven block and wherein the block is shown in two different positions.

[0138] FIG. 15 shows in a perspective view an embodiment of the bottom section of a slit-pocket of a chamber according to the invention.

[0139] FIG. 16 shows a block-diagram representation of a system according to the invention making use of a chamber according to the invention.

[0140] FIG. 17 shows in a schematic and simplified representation one embodiment of the system according to FIG. 16.

[0141] FIG. 18 shows a representation of occupation-times of the slit-pockets by workpieces at a slit-pocket staple.

[0142] The invention will now be further exemplified, somehow focused on degassing, with the help of figures.

[0143] FIG. 2 shows, most schematically and simplified, in a cross sectional representation, a part of a block 3 of a chamber 1 according to the invention. Within single piece block 3 of a metal, as of aluminum or of an aluminum alloy, or of a block 3 construed, as shown in dashed lines at 5, of multiple metal parts, mutually biased so as to establish narrowest thermal coupling, e.g. by screws or screw bolts not shown in FIG. 2, slit-pockets 7 are provided. The slit-pockets are mutually parallel and extend along slit-pocket planes E.sub.P. In the representation according to FIG. 2 the slit-pocket planes E.sub.P are parallel to the x/y plane of the coordinate system x/y/z. The slit-pockets 7 are stacked one upon the other whereby they are not necessarily aligned in y direction. The slit-pockets 7 comprise, as schematically shown, workpiece supports 9 for the workpieces as addressed above, which are not shown in FIG. 2.

[0144] The slit-pockets 7 have workpiece-handling openings 11. Whereas, in the embodiment of FIG. 2, each slit-pocket 7 has one single workpiece-handling opening 11, such workpiece-handling opening might additionally be provided at the end of the respective slit-pockets 7, opposite the workpiece-handling opening 11 shown.

[0145] The chamber 1 further comprises a door arrangement 13, schematically shown in FIG. 2, for freeing or covering selectively workpiece-handling openings 11 of the slit-pockets 7. As schematically shown in FIG. 2 by control input C 13 to the door arrangement 13, the door arrangement 13 is controllable with respect to the freeing/covering status of workpiece-handling openings 11.

[0146] FIGS. 3 to 5 most schematically and in a representation in analogy to that of FIG. 2 show examples of realizing the door arrangement 13 as of FIG. 2.

[0147] According to FIG. 3 the door arrangement 13 comprises a slider (not shown) or a flap 15, pivotably or slidably (not shown) mounted to block 3. Each of the flaps 15 or sliders is driven by a drive unit 17, controlled as shown at control input C.sub.17.

[0148] As shown in FIG. 2 in dashed lines and especially if the chamber 1 is a degasser chamber, gas feed lines 19 discharge in at least some, normally in all slit-pockets 7. The gas feed lines 19 are operationally connected to a pressurized gas source as schematically shown at 21 of FIG. 2.

[0149] Back to the embodiment of FIG. 3 and with an eye on establishing a gas flow F along and through the slit-pockets 7 by the gas feed lines 19, especially in an embodiment wherein the chamber 1 is a degasser chamber, the flaps 15 or sliders, in this embodiment, close the workpiece-handling openings 11 either in a gas-tight manner or in a leaky manner establishing a gas outlet for the gas flow F. Whether a flap 15 or slider seals the workpiece-handling openings 11 in a gas-tight manner or only in a leaky manner may be set by the control of drive unit 17.

[0150] According to FIG. 4a, the door arrangement 13 as of FIG. 2 is realized by a plate 23 and, as exemplified in FIG. 4a, one DWHO 25. In the example according to FIG. 4a, the plate 23 is operationally connected to a plate drive 27, controlled at C 27. The plate 23 is drivingly and controllably slid along a surface of block 3 so as to bring the DWHO 25 selectively in alignment with a workpiece-handling opening 11. Between plate 23 and block 3 a gap 28 is defined.

[0151] With an eye on an established the gas flow F, there is ongoingly provided a gas outlet between plate 23 and the surface of block 3 through the gap 28.

[0152] Departing from the representation of FIG. 4a, FIG. 4b addresses a further embodiment. In this embodiment and as shown also in FIG. 4a by the symbol S, plate 23 with DWHO 25 is kept stationary whereas block 3 with the slit-pockets 7 is operationally connected to a block drive 29, controlled as schematically shown at C.sub.29. By means of the block drive 29 the block 3 is slid along plate 23 to selectively bring the DWHO 25 in alignment with one of the workpiece-handling openings 11. Here too, the small interspace or gap 28 between the surface of block 3 and plate 23 provides for a gas flow passage from the slit-pockets 7 to the surrounding of the chamber 1.

[0153] The embodiment according to FIG. 5, again in a simplified and schematic representation in analogy to the representations of FIGS. 3 and 4, in fact departs from the embodiment according to FIG. 4b. It schematically shows an embodiment as practiced today. The plate 23 of FIG. 4b is realized by a wall 31 of an isolating housing 33 which is spaced from the surface of block 3 whereat the workpiece-handling openings 11 are provided. Block 3 is driven by block drive 29, controlled via C.sub.29, along wall 31 with the DWHO 35. A flap 37 or a slider is movably mounted to the wall 31 so as to close or free the DWHO 35. Thus the door arrangement of wall 31, DWHO 35 and flap 37 or slider either covers the workpiece-handling openings 11 or frees such workpiece-handling openings 11 towards the surrounding atmosphere AT of the chamber 1. This whenever block 3 is driven in a position in which a respective workpiece-handling opening 11 is aligned with the DWHO 35 and the flap 37 or slider is opened. The flap 37 or slider is controllably driven by a drive 39 which is controlled as schematically shown via control input C 39.

[0154] In all embodiments according to FIGS. 4 and 5 the plate or wall may comprise more than one of the DWHO either to free more than one of the workpiece-handling openings 11 simultaneously or to optimize the hub which must be run by the respective plate or by the block to subsequently free workpiece-handling openings 11.

[0155] With an eye on FIG. 5 and combined with the embodiment in which a gas flow F according to FIG. 2, e.g. as a degassing flush, is established, the following prevails: The gas flow F freely exits from the slit-pockets 7 into the interspace I between the wall 31 and the surface of block 3. This prevents cross-contamination of the slit-pockets 7. If such gas flow provides in interspace I a high enough pressure with respect to the pressure in the surrounding AT, it might even be possible to omit a flap 37 or slider.

[0156] In one embodiment, as practiced today, there is provided, in the wall of housing 33, a pumping port 41 to be operationally connected to a pump 43.

[0157] In the interspace I a pressure may be established which is slightly higher than the pressure in the surrounding AT, which is in practice mostly ambient pressure, so as to establish a gas flow from the interspace I to the surrounding AT whenever the flap 37 or slider frees the DWHO 35. Nevertheless and if the degassed products are harmful and should not be dispatched into the surrounding AT, then the pressure in the interspace I may be selected and controlled to be slightly lower than the pressure in the surrounding AT so as to establish a gas flow from the surrounding AT into the interspace I whenever the flap 37 or slider is open. The gas which is flown through the slit-pockets 7 from pressurized gas source 21 of FIG. 2 may be dried air if the respective workpiece to be treaded is uncritical which respect to oxidation, otherwise at least one of N2, Ar, He.

[0158] FIG. 6 shows schematically and simplified a part of a cross-section according to line A-A of FIG. 2 through a part of block 3. The coordinate system as introduced in FIG. 2 is also shown in FIG. 6. Each of the slit-pockets has a height h for which there is valid:

2.5 mm≤h≤50 mm.

[0159] This range of height h prevails for at least 30% or even for at least 50% of the overall surface areas of a slit-pocket 7 along the x/y plane which is parallel to slit-pocket plane E.sub.P according to FIG. 1. In the slit-pockets 7 the workpieces 50 as were addressed in the introductory part of the present description, are supported on workpiece supports 49 which, in the embodiment of FIG. 6, are realized by pieces of O-ring material mounted along the bottom surface of the slit-pocket 7. Thereby the workpiece supports 49 may be constructed in a lot of different variants but it should be made sure that the surface of the workpiece supports which contact the workpieces 50 provide therewith enough friction to ensure stable support of the workpieces 50. The workpieces 50 have a thickness D within the range of:

0.01 mm≤D≤5 mm.

[0160] In the bottom surface of the slit-pocket 7 one or more than one cutouts 51 may be worked. Such cutouts 51 may be necessary to allow an arm 53 of a handler, as shown in dashed lines, to enter the slit-pockets 7 beneath the support surfaces of the workpiece supports 49 so as to deposit or remove such workpiece 50.

[0161] The sections 52 of the block 3 which separate, in z-direction, directly neighboring slit-pockets 7, are in fact significant with respect to heat flow HF there along, mutual thermal decoupling of neighboring slit-pockets 7, as well as duration for establishing a stable temperature throughout the block 3.

[0162] It has been recognized that these sections 52 should have a thickness d for which there is valid:

0.5 mm≤d≤10 mm.

[0163] This thickness range d shall prevail along at least 30% or even 50% of the extended surface area of the respective slit-pockets 7 along the slit-pocket plane E.sub.P which is in FIG. 6 parallel to the x/y plane.

[0164] If the cutouts fulfill the addressed range for thickness d, they do contribute to the addressed at least 30% of the extent of the slit-pocket surface area to be considered.

[0165] The double-arrow I/O schematically represent the movement of the robot arm 53 into and out of slit-pockets 7.

[0166] The double arrow F represent the possibly established gas flow.

[0167] FIG. 6b shows in a representation in analogy to that of FIG. 6a an embodiment in which the section 52 comprises cutouts 51, 51a including through-cutouts as shown at 51a. If the surface area covered by such through-cutouts 51a and their width is small enough they might not substantially negatively influence heat flow, mutual decoupling of directly neighboring slit-pockets 7 and dynamic thermal behavior of the entire block 3.

[0168] One embodiment of a batch degasser chamber 71 according to the present invention is shown in FIG. 7. The block of thermally well conductive metal 72 features a plurality of slit-pockets 74. The sections of the block located between two neighboring slit-pockets 2 are labelled 75. The slit-pockets 74 may be machined in a one piece block of the metal or the block 72 is, as was addressed in FIG. 2 at ref.nr.5, assembled from several parts thereby ensuring a thermal behavior of the resulting block 72 which is only negligibly different from a single piece meal block 72. The sections 75 accord with the sections 52 of FIG. 6.

[0169] The block 72 is heated by heater elements 76 of heating arrangements 78 on the sidewalls 73 of the block 72. By using the side-walls 73 of block 72 and leaving empty top and bottom faces thereof, a homogeneous temperature profile along all the slit-pockets 74 is achieved.

[0170] The heating arrangements 78 with the respective heater elements 76 are biased, as by a multitude of screws (not shown) to the side faces or surfaces 73 of block 72. The arrows HF schematically indicate the heat flow from the heating arrangements 78 through block 72. The lateral or side surfaces 73 of block 72 form, in this embodiment, a heater interface to block 72.

[0171] If the addressed chamber with block 72 is tailored as a cooler chamber then the heating arrangements 78 are replaced by cooling arrangements with respective cooling elements, the surfaces 73 become cooler interfaces and the direction of heat flow HF is inversed.

[0172] As was already discussed in context with FIG. 6 also in this embodiment of the chamber with block 72, the bottom surfaces of the slit-pockets 74 comprise a central handler cutout 78 for introducing and removing a handling arm, 53 in FIG. 6, beneath the workpiece to be loaded or removed from the respective slit-pockets 74.

[0173] Again, if the height h of the slit-pocket 74 with respect to the bottom of the cutouts 78 exceeds the range described in context with FIG. 6a, such cutouts 78 should occupy less than 30% or less than 50% of the overall horizontal extent of slit-pocket 74. Clearly, such cutouts 78 may be only so deep that their areas contribute to that extent of slit-pocket 74 which fulfills the above mentioned range for the height h.

[0174] Dependent from the prevailing shape and thickness D of the workpiece 50, the height h is accordingly adapted.

[0175] The relation of prevailing workpiece shape and thickness and of the height h of the slit-pockets 74 is selected on one hand so as to optimize heat transfer between the top and bottom walls of the slit-pockets 74 and the workpiece, and, on the other hand, to allow a gas flow F along the extended surfaces of the workpieces 50, if such gas flow is desired. One should consider that the prevailing shape of a workpiece 50 (not shown in FIG. 7) may be due to the workpiece having a certain sagging in the slit-pocket due to its proper weight.

[0176] The chamber according to the invention shall be flexibly exploitable for differently tailored workpieces especially with respect to their thickness D and sagging characteristics.

[0177] As was addressed, slit-pockets 7, 74 of block 3, 72 shall be mutually thermally decoupled as well as possible so that loading and removing a workpiece 50 to or from one of the slit-pockets 7, 74 does only negligibly influent the directly neighboring slit-pockets in which a workpiece 50 is heat-treated. The thermal intercoupling between neighboring slip-pockets 7, 74 is primarily defined by the thickness of sections 52 (FIG. 6) or 75 (FIG. 7) which mutually separates neighboring slit-pockets 7, 74.

[0178] In view of the trend off for dimensioning of the section 52, 75, on one hand, for good mutual thermal decoupling of the slit-pockets 7, 74 and, on the other hand, establishing quick thermal equilibrium upon thermal disturbances and for providing an optimal number of slit-pockets 7, 74 along a given extent or height of the block 3, 72, the thickness d is selected, as was already addressed, to be within the following range:

0.5 mm≤d≤10 mm

[0179] FIG. 8 shows, simplified and schematically, an embodiment of the batch degasser chamber 1 according to the invention. The workpieces 50 to be heated are positioned on the workpiece supports 49, as on pins, inside the slit-pockets 74. Each of the slit-pockets 74 is preferably gas-supplied via a purge gas line 19 as of FIG. 2, which may be equipped with a filter 80 to avoid particles. The purge gas line 19 may comprise a shallow gas cavity 81 with a length pg intended to preheat the purge- or flush-gas in the heated degasser block 72 before it enters the slit-pockets 74. The gas inlet is arranged preferably in the upper portion of the slit-pockets opposite the workpiece handling openings 11 since it is the goal to achieve a gas flow along the workpieces 50, especially along the top surfaces thereof, where outgassing is especially required.

[0180] The batch degasser block 72 is positioned in a housing 86. This housing 86 may include an appropriate isolation 88 to avoid heat loss of the block 72. This concept of a fixed position of the block 72 inside the housing 86 is proposed for a workpiece loading robots with a transfer arm having a large hub or stroke of the vertical drive (z-drive). The maximum number of slit-pockets 74 of the degasser block 72 is then limited by the range of the vertical z-drive-stroke.

[0181] FIGS. 9a and 9b show a top view (a) and a horizontal cross section (b) through a slit-pocket 74 with a workpiece 50 placed on pins 49. The slit-pocket 74 is open to one side by the workpiece-handling opening 11 in order to allow loading and unloading the workpiece 50. On the opposite side the inner contour of the pocket is rounded to match the outer shape of a circular workpiece 50, here a wafer, and thus to enable a good heat transfer inside the block 72. The position of the pins 49 allows a safe operation of the workpiece 50 with the transfer arm 53. The inner contour of the slit-pocket 74 is just machined wide enough to take up the transfer arm 53 and the workpiece during transfer. Consequently the slit-pocket—74—volume is minimized and the spacer section—75—profile is maximized so that the best possible heat transfer is supported. The purge gas line 19 is arranged opposite to the workpiece-handling opening 11. A preheating gas cavity 81 can be a single straight line 83a or a network of distributed lines 83a, b, c.

[0182] The embodiment of FIG. 10, shown in a representation analogue to that of FIG. 8, accords principally with the embodiment of FIG. 4a. A door plate 90 has a flat, plate-shaped design of a size essentially twice the size of the front face of the block 72. It exhibits one DWHO 92 of approximately the same shape as the workpiece-handling opening 11, preferably arranged in the middle of the door plate 90 as shown in FIG. 10. The door plate 90 is vertically movable by the drive 27 in directions shown by arrow DP. Between the door plate 90 and the workpiece-handling opening 11 there is the gap 28. In FIG. 10 the door plate 90 is positioned with all slit-pockets 74 closed.

[0183] FIG. 11 shows the door plate 90 being positioned to load or unload a workpiece in the lowest slit-pocket 74.sub.l (left) and in the uppermost slit-pocket 74.sub.u (right). The door plate 90 allows to keep all slit-pockets 74 closed during a load/unload operation with the exception of the slit-pocket 74 to be accessed. The position can be determined either by means of a sensor or markings or electronically with the aid of a stepper motor as the driven 27.

[0184] An alternative embodiment is shown in FIG. 12 where the spacer sections 75 have such a thickness d that the DWHO 92 in the movable door plate 90 is covered by the front of the spacer sections 75 between two neighboring slit-pockets 74. This has advantages when operating the door plate 90 because there are many “fully closed between pockets” positions (one less than the number of slit-pockets 74). There is however the disadvantage that at a given maximum height of the degasser stack less workpieces 50 can be processed than in the version described above.

[0185] FIG. 13 shows another alternative embodiment with two door plates 90a, 90b independently controllably movable in the direction DPa, DPb. The two DWHO 92a, 92b are offset just so much to have a “closed” configuration. A through-opening DWHO can be quickly realized by aligning both openings 92a, 92b. This solution will allow for better thermal insulation while still allowing a compact arrangement of slit-pockets 74.

[0186] For all those embodiments the load operation will comprise: [0187] Determining an empty slit-pocket inside the degasser block. This can be realized either by a sensor giving a respective (occupied/free) signal or by an electronic controller supervising the status of the slit-pockets. Such a controller could also transmit an “all pockets full” signal to the Load/Unload handling system. [0188] Giving access to a free slit-pocket by aligning a DWHO with the respective workpiece-handling opening in the block. [0189] Placing a workpiece on a handler capable of performing a z-motion (i.e. vertically in embodiments according to FIGS. 10 to 12) and aligning the handler with the DWHO. [0190] Introducing the workpiece through the DWHO into the slit-pocket 74. [0191] Placing the workpiece on the workpiece supports. [0192] Retracting the handler from the slit-pocket. [0193] Covering the workpiece handling opening of the slit-pocket by the respective door plate.

[0194] Especially if a transfer arm 53 with a vertical z-drive is not available, an alternative solution—as today practiced—is to vertically move whole block 72 inside the housing 86 by a block drive 29 as shown in FIG. 14). This embodiment principally accords with the embodiment of FIG. 4b or FIG. 5. In this case there is at least one DWHO located at a defined position in the housing 86 which can be also provided with a flap 37 or slider (not shown in FIG. 14) according to FIG. 5, controlled, e.g. by the z-movement of the block 72. FIG. 14 shows the lowered “all-closed” position of block 72 as well as the upper position to load or unload the lowest slit-pocket 74 of the block 72 in the same sketch. The purge gas line 19 has to support the vertical movement of the block 72 by a flexible line 73 prior to the optional gas filter 80. The double-arrow DB shows the movement of block 72 in the housing 86.

[0195] The drive(s) for the vertical displacement of the door plates or of the block may be arranged above or below the block and will thus not block any space where the loading and unloading operation takes place.

[0196] A further requirement for a batch degasser is that it needs to be cleaned efficiently from time to time. Outgassing material may condense and accumulate at certain cool spots and result in contaminated surfaces, flaking or dust. For a multiple part block 3, as was addressed above and e.g. in context with FIG. 2 at 5, the design of such parts according to FIG. 15 has the advantage of a simplified manufacturing of the slit-pockets 7 and also their easy cleaning. In an Al plate 3a, a cavity is machined from the top, including a cut-out 51 for the transfer arm, an edge 49 as a workpiece support, and the gas inlet 19. The plate 3a has through-holes 96 on all the 4 corners to stack and bias a pile of any number of plates 3a in an easy way. It has to be mentioned that for regular applications with rigid substrates, the cut-out 51 for the transfer arm can be minimized since the transfer arm in atmospheric environment can hold a substrate with a vacuum gripper. In this case, for releasing the substrate no or only a small movement away (downwards in case of FIG. 15) is necessary to allow the retraction of the handler/gripper.

[0197] An important feature of the invention is that the block 3, 72 is made of thermally well conducting material. It is advantageous to have block 3, 72 embedded in a housing 31, 86, which supports preserving a uniform temperature profile. Door plates also contribute to this temperature uniformity. As soon as a workpiece is loaded into one of the slit-pockets 7, 74 a temporarily heat drain will occur. Example: To heat up a silicon wafer with 300 mm diameter and 0.77 mm thickness from room temperature to 150° C. requires energy of 11 kJoule. If this energy can be received from a slab of aluminium as the suggested spacer-section 52 with e.g. 320 mm diameter and e.g. 5 mm thickness, the temperature of this section 52 would be reduced by 17° C. However the heat exchange between the workpiece and the spacer-section 52 is relatively slow compared to the heat conductivity within the block 3, 72 so that due to help of the heater elements the block 3, 72 will not experience relevant temperature non-uniformity.

[0198] The proposed chamber is preferably run at atmospheric pressure. However the basic ideas may also be applied for low pressure degassing. An effective conductive heat transfer is possible if the gas pressure is >1 kPa.

[0199] Nitrogen is the preferred purge or flush gas since it avoids possible oxidation of pre-processed devices on the substrate. The heat conductivity of nitrogen is fairly good (see table below) and it has a low price. Argon or Helium may also be used. Helium has superior heat conductivity, however in this case it may be necessary to keep the leak rate low for cost reasons. On the other hand nitrogen has a better momentum transfer to the molecules to be removed, like water vapor due to similar masses. [0200] N2 0.026 W/m K [0201] Ar 0.0167 W/m K [0202] He 0.149 W/m K

[0203] A process sequence for a batch degasser according to the invention with n pockets may look like the following: [0204] 1) Heat the block to a temperature set point, typically 150° C. [0205] 2) Position DWHO to the lowest slit-pocket, No. 1 [0206] 3) Load a workpiece into slit-pocket No. 1 [0207] 4) Position DWHO in a covering position Adjust a flow of nitrogen to about 50 to 1000 sscm, preferably 100 sscm, in the slit-pocket No. 1 [0208] Repeat steps 2 to 5 for slit-pocket No. 2 up to slit-pocket No. n

[0209] Unloading will happen as follows, here described for slit-pocket No. 1:

[0210] 1) Switch off the nitrogen flow in slit-pocket No. 1 [0211] 2) Position the DWHO to slit-pocket No. 1 [0212] 3) Unload the workpiece from slit-pocket No. 1 to a vacuum load lock of a vacuum treatment tool. This should happen in the shortest possible time to avoid cool down of the substrate or condensation, unless such cool-down is desired for a subsequent workpiece processing. [0213] 4) Load a new workpiece in slit-pocket No. 1

[0214] For a continuous processing of workpieces the load/unload sequence is repeated accordingly. The sequences above basically describe a FIFO (first in first out) behavior. However, this may not be necessary when sufficient workpieces in the block have reached a thermal equilibrium, then a random access could be realized also.

[0215] The batch chamber according to the invention may incorporate at least one of the following features: [0216] A compact block made of a material with good heat conductivity with 6 to 50 cut out slit-pockets. The block may be made from a single piece or assembled from individual parts to form one compact block as described above. [0217] This block is heated from the side walls and may be located in an insulated housing. [0218] The slit-pockets having a minimal volume for safe workpiece handling in the slit-pockets, and to enable a good heat transfer from the side walls of the block to the inner of the slit-pockets. [0219] The spacer sections between the slit-pockets have an optimized height and are designed for providing an optimized heat transfer to the loaded workpieces. [0220] A sliding door plate between the block and a housing only opens the slit-pocket where a workpiece is required to be loaded or unloaded. [0221] Providing for a sliding door plate at least one position where all slit-pockets are closed. [0222] Alternatively the whole block is moving in a housing and a DWHO in the housing serves as shut-off for the slit-pockets.

[0223] A method to use such a batch chamber has at least one of the following features: [0224] In a continuous mode, so that each workpiece stays in a pocket for the same time (FIFO). [0225] Using nitrogen or another gas to transfer heat and flush degassing material. [0226] Allowing a minimal time for transfer of the workpiece to a vacuum load lock of a vacuum tool so as to avoid unnecessary cool down. Consequently the substrate may stay in the pocket until an empty load lock is available.

[0227] In FIG. 16 there is shown schematically a workpiece treatment system which makes use of the heat treatment chamber according to the invention. This chamber 100 is thereby constructed to have the following features: [0228] a) Each slit-pocket has a single workpiece-handling opening [0229] b) The slit-pockets are stacked in aligned manner in the block in the direction perpendicular to the slit-pocket, e.g. in vertical direction as the slit-pockets are oriented normally horizontally. [0230] c) Also the workpiece-handling opening of the slit-pockets are aligned in the addressed direction along the block without lateral displacement. [0231] d) The door arrangement frees the inside of the slit-pockets to ambient atmosphere of the surrounding denoted in FIG. 17 by AA.

[0232] Beside of the chamber 100 according to the invention and with the addressed limitation, there is provided a vacuum treatment arrangement 102 with a load-lock arrangement 104 separating vacuum atmosphere within the vacuum treatment arrangement from ambient atmosphere AA. There is further provided a magazine arrangement 106 with at least one magazine and possibly with an aligner (not shown). The load-lock arrangement 104 comprises workpiece supports whereupon workpieces are supported parallel to workpieces on the respective supports in chamber 100. Workpieces in the magazine arrangement 106 as well are supported parallel to such workpieces in the load-lock arrangement 104 and chamber 100. In spite of the fact that these planes of workpiece support may be different planes, their mutual distance, vertical to such planes, is minimized up to all these planes forming a single plane.

[0233] There is further provided a handling robot 108 which performs workpiece handling to and from the magazine arrangement 106, possibly via a further station, e.g. an aligner station, to and from the chamber 100, to and from the vacuum treatment arrangement 102 as shown with double-arrows and dashed lines. Such a system specifically tailored for degassing, i.e. making use of the addressed chamber 100 as a degasser chamber, is shown in a schematic and simplified manner in FIG. 17.

[0234] The chamber 100 according to FIG. 16 is realized as a degasser chamber 100.sub.dg. The handling robot 108 of FIG. 16 is realized as handling robot 108′ in ambient atmosphere AA and is constructed to convey single workpieces 50 to and from degasser chamber 100.sub.dg.

[0235] The vacuum treatment arrangement 102 of FIG. 16 is realized as a multi-station, single workpiece-treatment arrangement with a I/O load-lock 104′ for workpiece input and output and a number of stations for single workpiece vacuum treatment. These stations may, for example, include a cooling station 111 for cooling workpieces 50 arriving from the degasser chamber 100.sub.dg, which have to be further cooled down prior to subsequent vacuum processing. The processing direction for the workpieces 50 is indicated in FIG. 17 by the arrow Pr. Beside of the input/output load-lock 104′, the subsequent stations may further be etching stations, layer deposition stations as for PVD, reactive or non-reactive, for CVD plasma enhanced or non-plasma enhanced etc. as perfectly known to the skilled artisan.

[0236] The handling robot 108′ which is pivotable about a vertical axis 110 and has at least one extendable and retractable handling arm 112 performs loading and unloading of the load-lock 104′ by single substrates 50.

[0237] In the example as shown in FIG. 17, the magazine arrangement 106 comprises three discrete magazines and an aligner 114. The robot 108′ conveys vacuum treated workpieces from load-lock 104′ to an output-magazine and un-degassed workpieces from an input-magazine of the arrangement 106 to the degasser chamber 100.sub.dg.

[0238] In the specific example of FIG. 17 and for specific workpieces to be treated, there is additionally provided the aligner 114 by which the addressed workpieces 50 are geometrically aligned. Because in this specific embodiment untreated workpieces are input in a magazine 106.sub.a, then geometrically oriented in aligner 114 as addressed by the arrow (a) and are conveyed to the degasser chamber 100.sub.dg from the aligner 114 as shown by the arrow (b), it might be said that in fact the aligner 114 is part of the overall magazine arrangement 106. All the handling between all these stations and the chamber as provided in the system as shown, is performed solely by the robot 108′.

[0239] The approach according to such a system namely to convey workpieces to and form a chamber according to the invention, with the addressed limitations, and to and from at least two or more further stations thereby performing such conveying in ambient atmosphere, may clearly also be applied for cooling workpieces in the chamber 100 and for a large variety of other station configurations.

[0240] FIG. 18 depicts along a horizontal axis addressed with t the occupation time of 44 stacked slit-pockets by workpieces. The vertical axis addresses the number of the slit-pockets piled one above the other.

[0241] As may be seen in processing of the chamber, with a member n of slit-pocket, here n=44, only a minor number m, here m=10, of slit-pockets is exploited. This results from the fact that the workpieces, which are treated in this example necessitate a predetermined heat treating time A, and the workpieces are loaded in respective slit-pockets of the chamber subsequently with a time lag dT.

[0242] The number m of used slit-pockets in the chamber may be determined by forming the quotient of Δ/dT rounded to an integer. Thus, after the m of slit-pockets have been loaded with a time lag of dT, the timespan Δ for treatment of the workpiece which was first loaded, is lapsed and such workpiece may be unloaded from the respective slit-pocket. As apparent from the processing according to FIG. 17, the timespan dT which staggers subsequent loading operations to the chamber is in fact to be determined primarily by the throughput rate of the vacuum treatment arrangement 102.

[0243] As may further be seen in FIG. 18, representing in fact operation especially of the system according to FIG. 17, loading operation of workpieces to the chamber 100 is not subsequently performed in directly neighboring slit-pockets. As shown in FIG. 18 as an example, loading is performed in every second slit-pocket. Thus, and as seen from the occupation timespans according to the blackened columns in FIG. 18 during which a workpieces stay in the respective slit-pockets, loading according to the processing of FIG. 18 has occurred in the sequence of slit-pocket numbers: [0244] 3, 5, 7, 9, 10, 8, 6, 4, 2, 1.

[0245] Unloading is, according to FIG. 18 performed in the following sequence: [0246] 3, 5, 7, 9, 10, 8, 6, 4, 2, 1.

[0247] Consequently every slit-pocket may be unloaded from and immediately reloaded with a workpiece before propagating to unloading and loading the next slit-pocket in the sequence.

[0248] Loading and unloading not directly neighboring slit-pockets has the advantage that, the directly neighboring slit-pockets are significantly less affected by thermal disturbances as caused by the loading/unloading action.

[0249] Although the processing as shown in FIG. 18 is specifically exploited with the system as shown in FIG. 17, it may also be exploited in appropriate, different overall systems with the chamber of staggered slit-pockets according to the invention.