Dislocation reduction in non-polar iii-nitride thin films

Abstract

Lateral epitaxial overgrowth of non-polar III-nitride seed layers reduces threading dislocations in the non-polar III-nitride thin films. First, a thin patterned dielectric mask is applied to the seed layer. Second, a selective epitaxial regrowth is performed to achieve a lateral overgrowth based on the patterned mask. Upon regrowth, the non-polar III-nitride films initially grow vertically through openings in the dielectric mask before laterally overgrowing the mask in directions perpendicular to the vertical growth direction. Threading dislocations are reduced in the overgrown regions by (1) the mask blocking the propagation of dislocations vertically into the growing film and (2) the bending of dislocations through the transition from vertical to lateral growth.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS[0001]This application is a continuation of U.S. Utility patent application Ser. No. 11 / 852,908, entitled “DISLOCATION REDUCTION IN NON-POLAR III-NITRIDE THIN FILMS,” filed on Sep. 10, 2007, by Michael D. Craven, Steven P. Denbaars, James S. Speck, and Shuji Nakamura, attorneys docket number 30794.245-US-I1, which application is a continuation-in-part of the following application:[0002]U.S. Utility patent application Ser. No. 11 / 472,033, entitled “NON-POLAR (Al, B, In, Ga)N QUANTUM WELL AND HETEROSTRUCTURE MATERIALS AND DEVICES,” filed on Jun. 21, 2006, by Michael D. Craven, Stacia Keller, Steven P. DenBaars, Tal Margalith, James S. Speck, Shuji Nakamura, and Umesh K. Mishra, attorneys docket number 30794.101-US-D1, now U.S. Pat. No. 7,982,208, issued Jul. 19, 2011, which application is a divisional of U.S. Utility patent application Ser. No. 10 / 413,690, filed on Apr. 15, 2003, by Michael D. Craven et al., entitled “NON-POLAR (Al, B, In, Ga)N Q...

AI Technical Summary

Benefits of technology

The patent describes a method to reduce threading dislocations in non-polar III-nitride thin films. This is achieved by applying a thin patterned dielectric mask and then selectively epitaxial regrowth to achieve a lateral overgrowth based on the mask. This results in a reduction of threading dislocations in the overgrown regions due to the mask blocking the propagation of dislocations vertically into the growing film and the bending of dislocations through the transition from vertical to lateral growth.

Problems solved by technology

These polarization-induced electric fields affect the performance of current state-of-the-art optoelectronic and electronic nitride devices.

Discontinuities in total polarization result in the formation of fixed sheet charges at the corresponding interfaces or surfaces.

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