| US 7,598,108 B2 | ||
| Gallium nitride-on-silicon interface using multiple aluminum compound buffer layers | ||
| Tingkai Li, Vancouver, Wash. (US); Douglas J. Tweet, Camas, Wash. (US); Jer-Shen Maa, Vancouver, Wash. (US); and Sheng Teng Hsu, Camas, Wash. (US) | ||
| Assigned to Sharp Laboratories of America, Inc., Camas, Wash. (US) | ||
| Filed on Jul. 06, 2007, as Appl. No. 11/825,427. | ||
| Prior Publication US 2009/0008647 A1, Jan. 08, 2009 | ||
| Int. Cl. H01L 21/00 (2006.01) | ||
| U.S. Cl. 438—48 [438/172; 438/22; 257/103; 257/194; 257/E21.121; 257/E21.126] | 16 Claims |
| 1. A method for forming a thermal expansion interface between silicon (Si) and gallium nitride (GaN) films using multiple
buffer layers of aluminum compounds, the method comprising:
providing a (111) Si substrate;
depositing a first layer of AIN overlying the substrate, heating the substrate to a temperature within a first range;
depositing a second layer of AlN directly overlying and in contact with the first layer of AlN, hearing the substrate to a
temperature within a second range, lower than the first range;
depositing a third layer of AlN directly overlying and in contact with the second layer of AlN, heating the substrate to a
temperature within the first range;
forming a first grading Al1-XGaXN layer directly overlying and in contact with the third layer of AlN, where 0<X<1;
forming a first fixed composition Al1-XGaXN layer directly overlying and in contact with the first grading Al1-XGaXN layer, where 0<X<1; and,
growing a first epitaxial GaN layer directly overlying and in contact with the fixed composition Al1-XGaXN layer.
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