CRYSTAL GROWTH APPARATUS WITH MOVABLE SEED FIXTURE

Abstract

A crucible device for growing crystals includes a container being arrangeable in a heating chamber of a heating apparatus, and a seed fixture element. The container includes a base section and the seed fixture element includes a seed surface which is configured for attaching a seed crystal. The seed fixture element is moveable coupled to the base section such that the distance between the seed surface and the base section is adjustable.

Claims

1-13. (canceled)

14. A heating apparatus for growing crystals, the apparatus comprising a heating chamber (150), and a crucible device (100) for growing crystals, the crucible device (100) comprising a container (101) being arranged in the heating chamber (150) of the heating apparatus, and a seed fixture element (102), wherein the container (101) comprises a base section (103), wherein the seed fixture element (102) comprises a seed surface (104) which is configured for attaching a seed crystal (105), wherein the seed fixture element (102) is moveable coupled to the base section (103) such that the distance between the seed surface (104) and the base section (103) is adjustable, wherein the base section (103) comprises a receiving hole (106) in which the seed fixture element (102) is moveable in and out for adjusting the distance between the seed surface (104) and the base section (103) wherein at least one spacer element (108, 109) being arranged between the base section (103) and the seed fixture element (102), wherein at least the spacer element (108, 109) and the seed fixture element (102) are extractable in a telescopically manner for what reason the at least one spacer element (108, 109) comprises a further receiving hole in which the seed fixture element (102) is movably arranged and the spacer element (108, 109) is movable inside the receiving hole (106) of the base section (103).

15. The heating apparatus according to claim 14, wherein the base section (103) and the seed fixture element (102) are coupled by a screw connection such that upon rotating one of the base sections (103) and the seed fixture element (102) the distance between the seed surface (104) and the base section (103) is adjustable.

16. The heating apparatus according to claim 15, further comprising a rotating actuator (107) coupled to at least one of the base sections (103) and the seed fixture element (102) for rotating base section (103) and the seed fixture element (102).

17. The heating apparatus according to claim 14, further comprising an extractable lifting plunger for lifting the seed fixture element (102) with respect to the base section (103).

18. The heating apparatus according to claim 14, wherein the spacer element (108; 109) is coupled to at least one of the base sections (103) and the seed fixture element (102) by a screw connection such that upon rotating the spacer element (108; 109) the distance between the seed surface (104) and the base section (103) is adjustable.

19. The heating apparatus according to claim 14, wherein the base section (103) forms a bottom section or a top section, in particular a lid, of the container (101).

20. The heating apparatus according to claim 14, wherein the base section (103) and the seed fixture element (102) are arranged in such a manner that an extending direction between the base section (103) and the seed fixture element (102) may be between 1° and 89° with respect to a vertical direction.

21. The heating apparatus according to claim 14, further comprising a control unit (110) configured for controlling the distance between the seed surface (104) and the base section (103).

22. A method for growing crystals by the heating apparatus according to claim 14, the method comprising adjusting the distance between the seed surface (104) and the base section (103) by moving the seed fixture element (102) relative to the base section (103), for what reason at least one spacer element (108; 109) being arranged between the base section (103) and the seed fixture element (102), wherein at least the spacer element (108; 109) and the seed fixture element (102) are extractable in a telescopically manner for what reason the at least one spacer element (108, 109) comprises a further receiving hole in which the seed fixture element (102) is movably arranged and the spacer element (108, 109) is movable inside the receiving hole (106) of the base section (103).

Description

BRIEF DESCRIPTION OF THE DRAWING

[0035] The aspects defined above and further aspects of the present invention are apparent from the examples of embodiment to be described hereinafter and are explained with reference to the examples of embodiment. The invention will be described in more detail hereinafter with reference to examples of embodiment but to which the invention is not limited.

[0036] FIG. 1 shows a schematic view of the heating apparatus comprising the crucible device in an extracted state according to an exemplary embodiment of the present invention.

[0037] FIG. 2 shows a schematic view of the heating apparatus according to FIG. 1 in a retracted state according to an exemplary embodiment of the present invention.

[0038] FIG. 3 shows a schematic top view of a crucible device according to an exemplary embodiment of the present invention.

[0039] FIG. 4 shows a schematic view of a heating apparatus, wherein the base section is mounted to the top section of the container according to an exemplary embodiment of the present invention.

DETAILED DESCRIPTION OF EXEMPLARY EMBODIMENTS

[0040] The illustrations in the drawings are schematic. It is noted that in different figures similar or identical elements are provided with the same reference signs.

[0041] FIG. 1 and FIG. 2 show schematic views of the heating apparatus comprising a crucible device 100 for growing crystals in an extracted state (FIG. 1) and a retracted state (FIG. 2) according to an exemplary embodiment of the present invention.

[0042] The crucible device 100 comprises a container 101 being arrangeable a heating chamber 150 of a heating apparatus and a seed fixture element 102. The container 101 comprises a base section 103 and the seed fixture element 102 comprises a seed surface 104 which is configured for attaching a seed crystal 105. The seed fixture element 102 is moveable coupled to the base section 103 such that the distance d between the seed surface 104 and the base section 103 is adjustable.

[0043] The apparatus is a furnace comprising the heating chamber 150 which provides a heatable accommodation space for the crucible device 100. The apparatus 150 and the crucible 100, respectively, heat the inner volume of the container of the crucible device 100 until a desired temperature is reached. The temperature which may be provided inside the inner volume may be 100° C. to 1400° C., preferably to approximately 2100° C. or more. The heating chamber 150 may comprise an insulating material, such that the inner volume of the crucible 100 is thermally isolated from an environment, i.e. an intermediate volume, surrounding the housing.

[0044] The container 101 of the crucible device 100 comprises an inner volume in which the crystal growing takes place. Inside the container 101, a seed element 105 may be placed onto the seed surface 104 of the seed fixture element 102. The seed element 105 is made of a desired single crystal material, such as sapphire. Furthermore, a reaction fluid 111, such as a desired crystal material, e.g. high purity alumina crackle, is put into the inner volume of the container 101. The reaction fluid 111 may be injected by nozzles in the direction to the crystal 105. If the temperature inside the container 101 increases, the desired material within a reaction fluid growth onto a surface of the seed crystal 105. The container 101 may comprise a cylindrical shape having a circular, elliptical or rectangular base surface.

[0045] The seed fixture element 102 provides a seed surface 104 onto which the seed crystal 105 may be fixed, for example by clamping means and/or by gluing with adhesive materials.

[0046] The base section 103 is arrangeable onto a bottom element 112 of the container 101. The base section 103 comprises an accommodation space and a receiving hole 106 for the seed fixture element 102. For example, the base section 103 comprises a ring structure, wherein the seed fixture element 102 is moveable inside the inner ring structure 103.

[0047] The seed fixture element 102 is movable with respect to the base section 103 in order to adjust the distance d between the seed surface 104 and the growth surface onto the seed crystal 105, respectively, of the seed fixture element 102 and the base section 103 along an extending direction. The extending direction defines the moving direction of the seed fixture element 102 with respect to the base section 103.

[0048] The base section 103 comprises a receiving hole 106, in which the seed fixture element 102 is moveable in and out for adjusting the distance d between the seed surface 104 and the base section 103. The base section 103 comprises a hollow cylinder structure, in which the seed fixture element 102 (such as a solid cylindrical structure) is movable. Between the outer surface of the seed fixture element 102 and the inner surface of the base section 103, guiding structures, such as guiding rails or a thread, may be provided. Hence, the base structure 103 supports the seed fixture element 102 in a movable manner.

[0049] The base section 103 and the seed fixture element 102 are coupled by a screw connection such that upon rotating one of the base sections 103 and the seed fixture element 102 the distance d between the seed surface 104 and the base section 103 is adjustable. For example, the seed fixture element 102 may comprise an outer male thread and the base element may comprise in the receiving hole 106 an inner female thread being complementary and coupleable to the male thread. Hence, upon rotation, the seed fixture element 102 can be screwed inside and outside of the receiving hole 106.

[0050] The crucible device 100 further comprises a rotating actuator 107 coupled to at least one of the base sections 103 and the seed fixture element 102 for rotating the base section 103 with respect to the seed fixture element 103.

[0051] The crucible device 100 further comprises at least one spacer element 108, 109 being arranged between the base section 130 and the seed fixture element 102. The spacer element 108, 109 may be movably coupled to the base section 103 and the seed fixture element 102 may be movably coupled to the spacer element 108, 109. The spacer element 108 may comprise for example a further receiving hole in which the seed fixture element 102 is movably arrangeable. Additionally, the spacer element 109 may be movable inside the receiving hole 106 of the base section 103. As sown in FIGS. 1 and 2, a further spacer element 109 may be provided for example between the spacer element 108 and the base section 103. Accordingly, the further receiving hole is arranged within the spacer element 108, such that the seed fixture 102 element is movably inside the receiving hole of the spacer element 108. Furthermore, the spacer element 108 is movably inside the receiving hole of the further spacer element 109. In this manner, a plurality of spacer elements 108, 109 may be provided, so that a large distance d between the base section 1103 and the seed surface 104 can be bridged by the spacer elements 108, 109. Hence, upon adjusting the distance d between the seed surface 104 and the base section 103, the seed fixture element 102 is movable relatively to the spacer elements 108, 109 and the spacer elements 108, 109 are movable relatively to the base section 103.

[0052] Hence, the spacer elements 108, 109 and the seed fixture element 102 are extractable in a telescopically manner. As can be taken from FIG. 1, the seed fixture element 102, the spacer element 108 and the further spacer element 109 are shown in a maximum extracted position for providing the largest possible distance between the seed surface 104 and the base section 103. As can be taken from FIG. 2, the seed fixture element 102, the spacer element 108 and the further spacer element 109 are shown in a retracted position, wherein for example the seed surface 104 and the surface of the base section 103 are arranged within a common plane. For example, the crystal 201 and specifically the upper growing surface 202 may have a common distance d to the surface of the base section 103.

[0053] The crucible device 100 further comprises a control unit 110 configured for controlling the distance d between the seed surface 104 (and the growing surface 202, respectively) and the base section 103. For example, position sensors are arranged within the crucible device 100, wherein the position sensors detect the position of the growing surface 201 of the crystal 201 inside the container 101. Hence, upon receiving the position data of the position sensor, the control device 110 controls the distance d between the seed surface 104 of the seed fixture element 102 and the base section 103, such that the position of the growing surface 104 inside the container 101 may be kept constant. For example, the control unit 110 is coupled to the actuator for moving the seed fixture element 102 and/or the spacer elements 108, 109 in a translatory movement or a rotary movement.

[0054] The heating chamber 150 comprises a plurality of heating elements 151, which surround in particular an outer wall of the container 101 to provide a heat energy. The heating elements may also be arranged in the accommodation space between an outer wall of the chamber 150 and the sidewall of the container 101.

[0055] FIG. 3 shows a schematic top view of a crucible device 100 according to an exemplary embodiment of the present invention. The base section 103 comprises a receiving hole 106, in which the spacer elements 108, 109 and the seed fixture element 102 is moveable in and out for adjusting the distance d between the seed surface 104 and the base section 103. The base section 103 comprises a hollow cylinder structure, in which the seed fixture element 102 (such as a solid cylindrical structure) is movable.

[0056] FIG. 4 shows a schematic view of a heating apparatus, wherein the base section 103 is mounted to the top section of the container 101 according to an exemplary embodiment of the present invention. Hence, the base section 103 is arranged overhead at a top section, such as a lid, of the container 101. Hence, the seed fixture element 102 is movable from the top of the container 101 inside and to the center of the container 101. The extending direction of the seed fixture element 102 with respect to the base section 103 may be vertical.

[0057] The reaction fluid 111 may be provided in the liquid state and may be filled inside the container 101. the growing surface 202 of the crystal 201 is dipped in the liquid reaction fluid 111. Hence, the surface of the liquid reaction fluid 111 may be kept constant for example by injecting and draining respective reaction fluid 111. Furthermore, the distance d between the base section 103 and the seed surface 104 and the growing surface 202, respectively, may be adjusted such that the growing surface 202 is dipped with a predefined depth into the reaction fluid 111. The position of the growing surface 202 with respect to the surface of the reaction fluid 111 may be monitored by respective sensors, such that for example the control unit 110 may adjust the distance d in response to the data of the respective sensors.

[0058] It should be noted that the term “comprising” does not exclude other elements or steps and “a” or “an” does not exclude a plurality. Also elements described in association with different embodiments may be combined. It should also be noted that reference signs in the claims should not be construed as limiting the scope of the claims.

LIST OF REFERENCE SIGNS

[0059] 100 crucible device [0060] 101 container [0061] 102 seed fixture element [0062] 103 base section [0063] 104 seed surface [0064] 105 seed crystal [0065] 106 receiving hole [0066] 107 rotating actuator [0067] 108 spacer element [0068] 109 spacer element [0069] 110 control unit [0070] 111 reaction fluid [0071] 112 bottom element [0072] 150 heating chamber [0073] 151 heating element [0074] 201 crystal [0075] 202 growing surface [0076] d distance