Single-crystal – oriented-crystal – and epitaxy growth processes; – Forming from vapor or gaseous state
Reexamination Certificate
2007-04-03
2007-04-03
Gupta, Yogendra N. (Department: 1722)
Single-crystal, oriented-crystal, and epitaxy growth processes;
Forming from vapor or gaseous state
C117S101000, C117S950000, C117S951000, C117S952000
Reexamination Certificate
active
09904131
ABSTRACT:
A substrate comprising at least two layers which have different thermal expansion coefficients (TECs) is used for subsequent epitaxial growth of semiconductors. A typical example is an epitaxial growth of III-V Nitride (InGaAlBNAsP alloy semiconductor) on sapphire. Due to the thermal mismatch between III-V Nitrides and sapphire, epitaxially-processed wafers bow in a convex manner during cool down after the growth. A layered substrate compensates for the thermal mismatch between the epitaxial layered the top layer of the substrate, resulting in a flat wafer suitable for subsequent processing at high yields. The layered substrate is achieved by attaching to the back side of the substrate a material which has a lower TEC, for example silicon on the backside of the sapphire, to reduce or eliminate the bowing. Silicon is attached or grown on a sapphire wafer by such as wafer bonding or epitaxial growth. Since the above attachment process is done at an elevated temperature, the sapphire on silicon structure may bow in a convex manner at room temperature due to the thermal mismatch. Hence, for the subsequent growth of GaN on the sapphire on silicon wafer, direct heating is desirable rather than heating on a heat sink material. Another example is simultaneous epitaxial growths of GaN on a front side and silicon on the backside of the sapphire. A special growth system for this double-sided growth is also described.
REFERENCES:
patent: 3922703 (1975-11-01), Pankove
patent: 4312921 (1982-01-01), Hirai et al.
patent: 4348803 (1982-09-01), Sasaki
patent: 4395438 (1983-07-01), Chiang
patent: 4511816 (1985-04-01), Mikoshiba et al.
patent: 4830984 (1989-05-01), Purdes
patent: 4835116 (1989-05-01), Lee et al.
patent: 4846931 (1989-07-01), Gmitter et al.
patent: 5081519 (1992-01-01), Nishimura
patent: 5227331 (1993-07-01), Westmoreland
patent: 5290393 (1994-03-01), Nakamura
patent: 5356831 (1994-10-01), Calviello et al.
patent: 5562770 (1996-10-01), Chen et al.
patent: 5620557 (1997-04-01), Manabe et al.
patent: 5679152 (1997-10-01), Tischler et al.
patent: 5753551 (1998-05-01), Sung
patent: 5913974 (1999-06-01), Habuka
patent: 5919305 (1999-07-01), Solomon
patent: 6086673 (2000-07-01), Molnar
patent: 6110279 (2000-08-01), Kito et al.
patent: 6110811 (2000-08-01), Pey
patent: 6153010 (2000-11-01), Kiyoku et al.
patent: 6232137 (2001-05-01), Sugawara et al.
patent: 6316361 (2001-11-01), Hansson
patent: 6768175 (2004-07-01), Morishita et al.
patent: 198 47 101 (2000-05-01), None
patent: 53028374 (1978-03-01), None
patent: 60-154524 (1985-08-01), None
patent: 10335700 (1998-12-01), None
patent: WO 9965068 (1999-12-01), None
patent: WO 00/19500 (2000-04-01), None
Patent Abstracts of Japan. Abstract of JP 60-154524 (1985).
Olsen et al. “Calculated stresses in multilayered heteroepitaxial structures”, Jun. 1977, Journal of Applied Physics, vol. 48, No. 6, pp. 2543-2547.
Olsen et al. “Calculated stresses in multilayered heteroepitaxial structures”, Journal of Applied Physics, vol. 48, No. 6, Jun. 1977, pp. 2543-2547.
Patent Abstracts of Japan. English Abstract of JP 53-028374 (1978).
Gupta Yogendra N.
McDermott & Will & Emery
Song Matthew J.
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