JP2010241679A5 - - Google Patents

Claims (14)

A method for producing an AlN massive single crystal (2), comprising:
a) a single crystal AlN seed crystal (15) having a central central longitudinal axis (18) is placed in the crystal growth region (4) of the crucible device (3);
b) During the growth phase, an AlN growth gas phase (16) is produced in the crystal growth region (4), which is the AlN raw material (in the storage region (5) of the crucible device (3)). 14, 21), and the AlN bulk single crystal (2) is precipitated on the AlN seed crystal (15) from the AlN growth gas phase (16), thereby the central longitudinal axis (18). Grows in a growth direction (17) oriented parallel to the
c) at least the oxygen proportion of the AlN raw material (14, 21) is reduced during the purification phase;
d) the crucible device (3) includes a precipitation chamber (8), in which oxygen-containing components evaporated from the AlN raw materials (14, 21) during the purification stage are deposited;
e) A method in which the AlN raw materials (14, 21) are kept in an oxygen-free atmosphere during the entire growth phase after the purification phase is completed.   The method according to claim 1, wherein anharmonic evaporation of oxygen-containing components from the AlN raw material (14, 21) is caused during the purification step.   After the purification step is completed, the precipitation chamber (8) has the storage region (5) and the crystal to prevent gas exchange between the precipitation chamber (8) and the crystal growth region (4). The method according to claim 1 or 2, wherein the method is mechanically separated from the growth region (4).   The storage region (5) as viewed in the direction of the central longitudinal axis (18) is arranged between the crystal growth region (4) and the precipitation chamber (8). the method of. Wherein the deposition chamber even during purification stage (8) in a precipitation temperature (T ₃₎ is adjusted, the precipitation temperature is not lower than the storage area (5) within the adjusted storage temperature (T ₂₎ A method according to one of claims 1 to 4. During the purification step, the crystal temperature (T ₁ ) in the AlN seed crystal (15) is adjusted, and the crystal temperature is at least the same as the storage temperature (T ₂ ) adjusted in the storage region (5). The method according to one of claims 1 to 5. During the growth phase, the crystal temperature (T ₁ ) is adjusted at the growth interface of the growing AlN bulk single crystal (2), and the crystal temperature is adjusted to the storage temperature (T ₂ ) adjusted in the storage region (5). the method according to to one of 6) low had claims 1 Ri good. Said additional Purosesuga scan the crucible device (3) is supplied during the cleaning step, the process gas partial pressure of the process gas one of claims 1 to 7 is adjusted to be lower than during the growth phase The method described. Wherein is supplied additionally Purosesuga scan the crucible device (3), during the purification step, the claim process gas partial pressure of the process gas is adjusted to a value in the range of ² × 10 2 ~10 ⁵ Pa 1 9. The method according to one of items 8 to 8.   The method according to one of the preceding claims, wherein the growth stage is carried out directly following the purification stage. The storage area (5) is formed as an internal crucible insert (6) of the crucible device (3), and the AlN raw material (14, 21) required for the growth stage later is the start of the purification stage. The method according to one of claims 1 to 10 , wherein the method is completely introduced into the inner crucible insert (6) before. A disc-shaped single crystal AlN substrate having an oxygen concentration of 5 × 10 ¹⁶ cm ⁻³ at maximum. The AlN substrate according to claim 12, wherein the oxygen concentration is 1 × 10 ¹⁵ cm ⁻³ at maximum. The AlN substrate according to claim 12 or 13, wherein the AlN substrate has a substrate main surface, and the substrate main surface has a diameter of at least 75 mm .