CPC H01L 29/778 (2013.01) [H01L 21/02378 (2013.01); H01L 21/02381 (2013.01); H01L 21/0242 (2013.01); H01L 21/02458 (2013.01); H01L 21/02505 (2013.01); H01L 21/0254 (2013.01); H01L 29/267 (2013.01); H01L 29/2003 (2013.01); H01L 29/7786 (2013.01)] | 11 Claims |
1. A method of forming a type III-V semiconductor device, the method comprising:
providing a type IV semiconductor substrate comprising a main surface;
forming a type III-V semiconductor channel region over the type IV semiconductor substrate, the type III-V semiconductor channel region comprising a two-dimensional carrier gas,
forming a type III-V semiconductor lattice transition region between the type IV semiconductor substrate and the type III-V semiconductor channel region, the type III-V semiconductor lattice transition region being configured to alleviate mechanical stress arising from lattice mismatch between the type IV semiconductor substrate and the type III-V semiconductor channel region,
wherein forming the type III-V semiconductor lattice transition region comprises:
forming a first lattice transition layer over the type IV semiconductor substrate, the first lattice transition layer having a first metallic concentration;
forming a second lattice transition layer directly on the first transition layer, the second lattice transition layer having a second metallic concentration different from the first metallic concentration;
forming a third lattice transition layer directly on the second transition layer, the third lattice transition layer having a third metallic concentration that is higher than the first metallic concentration; and
forming a fourth lattice transition layer directly on the third transition layer, the fourth lattice transition layer having a fourth metallic concentration that is greater than 0 percent and is lower than the first metallic concentration.
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8. A method of forming a type III-V semiconductor device, the method comprising:
providing a type IV semiconductor substrate comprising a main surface;
forming a type III-V semiconductor lattice transition region over the main surface of the semiconductor substrate; and
forming a type III-V semiconductor channel region over the type III-V semiconductor lattice transition region, the type-III-V semiconductor channel region comprising a two-dimensional carrier gas,
wherein the type III-V semiconductor lattice transition region is electrically inactive and is configured to alleviate lattice mismatch between the type IV semiconductor substrate and the type III-V semiconductor channel region, and
wherein forming the type III-V semiconductor channel region comprises:
forming a first lattice transition layer over the type IV semiconductor substrate, wherein the first lattice transition layer is a layer of AlGaN;
forming a second lattice transition layer directly on the first transition layer, wherein the second lattice transition layer is a layer of AlGaN with a different aluminum content than the first lattice transition layer;
forming a third lattice transition layer directly on the second transition layer, wherein the third lattice transition layer is a layer of AlGaN with a higher aluminum content than the first lattice transition layer; and
forming a fourth lattice transition layer directly on the third transition layer, wherein the fourth lattice transition layer is a layer of AlGaN with a lower aluminum content as the first lattice transition layer.
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