System for manufacturing a high-quality semiconductor single crystal, and method of manufacturing same

1 . Sublimation system for growing at least one single crystal of a semiconductor material by means of a sublimation growing process, the sublimation system ( 100 ) comprising:

a crucible ( 102 ) having a longitudinal axis ( 120 ) and comprising a fixing means for at least one seed crystal ( 110 ) and at least one source material compartment ( 104 ) for containing a source material ( 108 );

a heating system being formed to generate an irregular temperature field around a circumference of the crucible ( 102 ) and/or along the longitudinal axis of the crucible ( 102 ); and

a thermal insulation unit ( 117 ) at least partly surrounding the crucible ( 102 );

wherein the thermal insulation unit ( 117 ) has a radially and/or axially asymmetric form to compensate the irregular temperature field,

wherein the heating system is formed with an asymmetry that causes an asymmetry in the generated temperature field,

wherein the thermal insulation unit ( 117 ) is structured with one or more discontinuities in a longitudinal direction along the longitudinal axis ( 120 ), and

wherein each discontinuity is positioned at a radial position that causes the discontinuity of the thermal insulation unit ( 117 ) to compensate the asymmetry of the heating system.

2 . Sublimation system according to claim 1 , wherein the heating system comprises an induction coil ( 116 ) operable to generate an electro-magnetic field and/or a resistive heating coil ( 116 ), at least partly surrounding the crucible ( 102 ).

3 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) comprises a needled carbon felt and/or densified carbon short fibers.

4 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) comprises a bendable sheet of carbon material, which is wrapped around the crucible ( 102 ) and comprises a stitching ( 304 ), at least one cramp ( 306 ), and/or an overlap region.

5 . Sublimation system according to claim 1 , wherein the heating system comprises a metallic strut member.

6 . Sublimation system according to claim 2 , wherein the coil ( 116 ) has a deformed cross-section in at least one of its windings, and/or wherein the coil ( 116 ) has at least one winding, which is arranged to have a different distance from its neighboring windings.

7 . Sublimation system according to claim 2 , wherein the coil ( 116 ) comprises at least one electrical contact ( 124 ), which is arranged at an axial position adjacent to the crucible ( 102 ).

8 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) has a cylindrical shape with a varying wall thickness around its circumference.

9 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) comprises one or more slots ( 308 ) forming at least one gap or a trench.

10 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) is formed by a plurality of separate parts which are assembled to have junctions extending in a radial and/or an axial direction.

11 . Sublimation system according to claim 1 , wherein the thermal insulation unit ( 117 ) is formed by a sheet of insulating material, which is arranged around the crucible forming an abutting joint, a slanted abutting joint, and/or an overlapping joint.

12 . Method of growing at least one single crystal of a semiconductor material by means of a sublimation growing process, the method comprising:

providing a crucible ( 102 ) having a longitudinal axis ( 120 ), fixing at least one seed crystal ( 110 ) at a fixing means of the crucible, and filling a source material ( 108 ) into at least one source material compartment ( 104 );

generating, by means of a heating system, an irregular temperature field around a circumference of the crucible ( 102 ) and/or along the longitudinal axis of the crucible ( 102 );

wherein a thermal insulation unit ( 117 ) is provided which is at least partly surrounding the crucible ( 102 ), and which has a radially and/or axially asymmetric form to compensate the irregular temperature field,

wherein the heating system is formed with an asymmetry that causes an asymmetry in the generated temperature field,

wherein the thermal insulation unit ( 117 ) is structured with one or more discontinuities in a longitudinal direction along the longitudinal axis ( 120 ), and

wherein each discontinuity is positioned at a radial position that causes the discontinuity of the thermal insulation unit ( 117 ) to compensate the asymmetry of the heating system.

13 . Method according to claim 12 , wherein the temperature field acting on the growing single crystal causes a growth rate measured around a defined circumference of the single crystal to differ for any two points along the circumference by at least 0.1 μm/h and not more than 10 μm/h, preferably by 0.7 μm/h.

14 . Method according to claim 12 , wherein the temperature field acting on the growing single crystal causes the finally grown single crystal to have a distribution of length values between a back surface of the single crystal and a top surface of the single crystal, measured along a defined circumference of the single crystal, which differ from a mean value by not more than 10%, preferably by not more than 5%.

15 . Method according to claim 13 , wherein the defined circumference is an outer circumference of the finally grown single crystal, or wherein the defined circumference is a radial distance from the center of the finally grown single crystal, which corresponds to a diameter of a substrate produced from the finally grown single crystal.