SEPARATING DEVICE FOR THE CHIP-FREE CUTTING OF WAFERS OF DONOR SUBSTRATES

Abstract

The present invention relates to a device (1) for separating at least one wafer from a donor substrate (2). The device (1) according to the invention comprises at least a housing (4) with a receiving space (6) for receiving at least one multi-layer arrangement (8) which consists of at least one donor substrate (2) and a receiving layer (10) arranged or generated thereon, and an application device (12) for the contactless application of the multi-layer arrangement (8) for generating crack-conducting stresses in the multi-layer arrangement (8).

Claims

1. Device (1) for cutting of at least one solid body portion, in particular a wafer, from a donor substrate (2), in particular an ingot, at least comprising a housing (4) with a receiving space (6) for receiving at least one multi-layer arrangement (8), consisting of at least one donor substrate (2) and one receiving layer (10) arranged or generated thereon, and an application device (12) for the contactless application of the multi-layer arrangement (8) for generating crack conducting stresses in the multi-layer arrangement (8).

2. Device according to claim 1, characterised in that crack initiating stresses are also generated without contact by the application device (12).

3. Device according to claim 1, characterised in that a crack initiating device (14) is provided to initiate the crack, wherein a crack initiation can be effected by the crack initiating device (14) either contactlessly or by contact with the multi-layer arrangement (8), in particular the donor substrate (2).

4. Device according to any one of the preceding claims, characterised in that the application device (12) is designed to introduce a fluid substance into the receiving space (6), wherein the temperature of at least a part of the multi-layer arrangement (8), particularly the receiving layer (10), can be controlled by means of the fluid substance in such manner that the crack initiating stresses and/or the crack conducting stresses are generated in the donor substrate (2) via the receiving layer (10), wherein the receiving layer has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the donor substrate (2) by at least an order of magnitude, wherein stresses are created in the solid body (2) by the thermal shocking of the receiving layer (10) in such manner that the stresses lead to a crack in the solid body (2) along a separation area, by which the solid body portion is separated from the solid body (2).

5. Device according to any one of the preceding claims, characterised in that the application device (12) includes a plurality of feed means (16, 18, 20) for feeding the fluid substance, in particular liquid nitrogen, wherein the fluid substance can be sprayed into the receiving space (6) in the form of a mist through at least one of the feed means (16, 18, 20), wherein preferably at least one of the feed means (20) is configured or operable in such manner that a crack initiation can be caused be means of said feed means (20), wherein die receiving layer has a coefficient of thermal expansion that differs from the coefficient of thermal expansion of the donor substrate (2) by at least one order of magnitude, wherein stresses are created in the solid body (2) by the thermal shock from the receiving layer (10) in such manner that the stresses initiate a crack in the solid body (2), by which the solid body portion is separated from the solid body (2).

6. Device according to any one of the preceding claims, characterised in that the receiving space (6) is designed such that it can be evacuated, wherein preferably a pump device, particularly a vacuum pump (22) is provided, which forms an operative connection with the receiving space (6).

7. Device according to any one of the preceding claims, characterised in that a holding and/or homogenising device (24) is arranged in the receiving space (6) for holding and/or homogenising the fluid substance which is introduced into the receiving space (6), wherein the holding and/or homogenising device (24) is preferably tubular, particularly annular in shape.

8. Device according to any one of the preceding claims, characterised in that a heating device (26) for controlling the temperature of the donor substrate (2) is arranged in the receiving space (6) or on the housing (4), wherein heating of the donor substrate (2) preferably from a temperature below 0° C., in particular below −50° C. or below −100° C. or below −150° C., to room temperature can be effected by the heating device (26).

9. Device according to any one of the preceding claims, characterised in that a spring-mounted or damped catching device (28) is arranged in the receiving space (6) for springy or damped catching of the separated solid body portion, wherein the spring-mounted or damped catching device (28) is preferably arranged on the holding and/or homogenising device (24).

Description

[0025] In the drawing:

[0026] FIG. 1 is a schematic representation of the devices that cooperate inside the receiving space of the device according to the invention; and

[0027] FIG. 2 is a schematic view from the outside of the separating device according to the invention.

[0028] FIG. 1 shows device 1 according to the invention for cutting at least one solid body portion, in particular a wafer, e.g., an 8-inch wafer, from a donor substrate 2. It is evident from the representation that the separating device according to the invention preferably includes at least a housing 4 with a receiving space 6 for receiving at least one multi-layer arrangement 8, wherein multi-layer arrangement 8 preferably has a donor substrate 2 and a receiving layer 10 arranged or generated thereon, and an application device 12 for the contactless loading of multi-layer arrangement 8 to generate at least crack conducting stresses in multi-layer arrangement 8.

[0029] Reference sign 14 preferably identifies a crack initiating device for starting the crack, wherein crack initiation by means of crack initiating device 14 may preferably be effects without contact or by contact with multi-layer arrangement 8, particularly donor substrate 2. In the case shown, the crack initiating device is preferably designed as a special feed means 20 for feeding the fluid substance, particularly liquid nitrogen.

[0030] Application device 12, which preferably comprises feed means 16, 18, 20, preferably serves to introduce the fluid substance into receiving space 6. The temperature of at least a portion of multi-layer arrangement 8, particularly of receiving layer 10, is controllable, particularly coolable, by means of the fluid substance, to such effect that the crack initiating stresses and/or the crack conducting stresses are generated by compression of receiving layer 10 in donor substrate 2. Feed means 16, 18, 20 or one of the feed means or at least one of the feed means is preferably designed as a spray nozzle or includes the spray nozzle. The one or more other feeds are then preferably designed to atomise the fluid substance, particularly the liquid nitrogen.

[0031] Housing 4 is preferably closable in such manner that receiving space 6 may be evacuated. Preferably a pump device, particularly a vacuum pump 22, is provided, which forms an operative connection with receiving space 6 such that the freely movable substances, particularly impurities such as gases or liquids or dust, can be ejected from receiving space 6 via the operative connection.

[0032] Reference sign 24 denotes a holding and/or homogenising device for holding and/or homogenising the fluid substance which is introduced into receiving space 6, which device is preferably arranged in receiving space 6. Holding and/or homogenising device 24 is preferably tubular, particularly annular or ring-shaped.

[0033] In addition, a heating device 26 is preferably arranged in receiving space 6 or on housing 4 to control the temperature of the donor substrate 2.

[0034] Reference sign 28 refers to a spring-mounted or damped catching device, which is arranged preferably above the donor substrate, in the longitudinal direction of the donor substrate in receiving space 6, preferably for springy or low-impact receiving of the separated wafer.

[0035] Multi-layer arrangement 8 is preferably aligned and/or fixed with the aid of a positioning and/or fixing device 32. The positioning and/or fixing device preferably cooperates in friction-locking and positive-locking manner with multi-layer arrangement 8.

[0036] FIG. 2 shows another schematic view of housing 4 of separating device 1. This view shows the presence of an opening and closing device 30, which is designed to introduce the multi-layer arrangement 8 into receiving space 6 or to take the separated solid body portion and the reduced donor substrate 2 out of receiving space 6. Opening and closing device 30 is preferably closable in such manner that a partial vacuum or a vacuum or substantially vacuum-like conditions with respect to the ambient pressure may be created in the interior of housing 4, in particular in receiving space 6.

[0037] Housing 4 of device 1 according to the invention particularly preferably extends less than 100 cm, more particularly less than 60 cm or less than 50 cm in the lateral direction. Housing 4 preferably extends up to 30 cm or exactly 30 cm or up to 35 cm or up to 40 cm in the lateral direction. Housing 4 of device 1 according to the invention particularly preferably extends less than 100 cm, more particularly less than 60 cm or less than 50 cm in the lengthwise direction. Housing 4 preferably extends up to 30 cm or exactly 30 cm or up to 35 cm or up to 40 cm in the lengthwise direction. Housing 4 of device 1 according to the invention particularly preferably extends less than 100 cm, more particularly less than 60 cm or less than 50 cm in the upward direction. Housing 4 preferably extends up to 30 cm or exactly 30 cm or up to 35 cm or up to 40 cm in the upward direction. Because of the small dimensions of the housing, it is not difficult to perform multiple separation processes of solid body portions simultaneously by placing a relatively large number of devices according to the invention in a small space.

[0038] For cutting the solid body portion, the following steps are preferably carried out: preferably in a first step, multi-layer arrangement 8 is introduced into receiving space 6. Then, a vacuum is preferably created. In a further step, the fluid material, particularly liquid nitrogen is introduced, particularly sprayed, into receiving space 6, preferably from above. In this way, the temperature of receiving layer 6 and/or of donor substrate 2 may be controlled, particularly cooled, extremely precisely. Receiving layer 6 is preferably cooled by the fluid material to a temperature below the glass transition temperature of the material of receiving layer 6. Particularly preferably, a small part of multi-layer arrangement 8, in particular of donor substrate 2 and/or receiving layer 6 is cooled in a closely defined manner via a feed means 20 preferably in the form of a split nozzle. In this context, a small part is understood to be an area preferably smaller than one third or smaller than one sixth or smaller than one tenth of smaller than one twentieth of smaller than one thirtieth of the surface area of receiving layer 6. In a further step a movement of the separated solid body portion or wafer is preferably cushioned or damped by a catching device 28 or spring-mounted and/or damping device, so that the separated, particularly split solid body portion comes to rest on the donor substrate 2 or workpiece. After the solid body has been cut, the donor substrate is preferably heated to a temperature above 0° C., preferably above 10° C. and particularly preferably to room temperature, by means of a heating device 26, particularly an electric resistance heater. In a last step, housing 4 is opened and the separated solid body portion is removed from receiving space 6. It is further conceivable for the donor substrate 2 to be replaced as well, or for the donor substrate to be coated with a fresh receiving layer.

LIST OF REFERENCE SIGNS

[0039] 1 Device [0040] 2 Donor substrate [0041] 4 Housing [0042] 6 Receiving space [0043] 8 Multi-layer arrangement [0044] 10 Receiving layer [0045] 12 Application device [0046] 14 Crack initiation device [0047] 16 First feed means [0048] 18 Second feed means [0049] 20 Third feed means [0050] 22 Pump device [0051] 24 Holding and/or homogenising device [0052] 26 Heating device [0053] 28 Catching device [0054] 30 Opening and closing device [0055] 32 Positioning and/or fixing device