Composition for off-axis growth sites on non-polar substrates
AssigneeLucent Technologies Inc.
InventorsKeith Wayne Goossen, James A. Walker
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Abstract
Nonpolar substrates comprising off-axis growth regions for the growth of polar semiconductors, and a method for making such substrates, are disclosed. According to the invention, an erodible material, such as a photoresist, is applied to a substrate at a site and is exposed to radiation at that site which has an linear variation in energy at the surface of the erodible material. Due to this variation in exposure energy, a taper results in the erodible material after development. The tapered region is then etched in a manner which etches both the erodible layer and the underlying substrate. The taper in the erodible layer provides a varying attenuation during the etching process such that the taper of the erodible layer is transferred to the substrate.
Claims20
A nonpolar substrate comprising a first region having a standard <100>
- surface and a second region having an off-axis surface suitably oriented for growing polar semiconductors, wherein polar semiconductors are grown on the off-axis surface and not on the standard <100>
- surface and the second region is completely surrounded by the first region.
A nonpolar substrate suitable for polar semiconductor growth comprising a first region having a standard <100>
- surface and a second region, wherein the second region is completely surrounded by the first region, wherein the second region has a planar surface which is oriented at a non-zero angle with respect to the surface of the first region, wherein the angle formed by the surface of the second region and the surface of the first region is towards the <110>
- plane, and wherein polar semiconductors are grown in the second region on the planar surface and not on the standard <100>
- surface.
Dependencies are inferred from the claim text.