Cleaved GaN facets by wafer fusion of GaN to InP

Abstract

Basal plane sapphire is a common substrate for the heteroepitaxy of GaN. This presents a challenge for fabrication of cleaved-facet GaN lasers because the natural cleavage planes in (0001) α-Al2O3 are not perpendicular to the wafer surface. This letter describes a method for achieving perpendicular cleaved facets through wafer fusion that can potentially be used to fabricate GaN based in-plane lasers. We demonstrate successful fusion of GaN to InP without voids or oxide at the interface and fabricate optically flat cleaved GaN facets that are parallel to the crystallographic planes of the host InP. I–V measurements have been performed across the n-N fused interface. These results show that the fused junction exhibits a barrier of several electron volts for electrons passing from the InP to the GaN and ohmic conduction of electrons moving in the opposite direction.

Cleaved Mirrors for Nitride Semiconductor Lasers

“…Another cleaving approach was reported by Sink et al 3 A sapphire substrate was directly bonded to an InP(100) substrate. After lapping down the sapphire thickness, nitride facets were made by cleaving the bonded sample along the InP(110) crystalline direction.…”

Wafer Fusion Technique Applied to GaN/GaN System

“…The technique has been applied to a number of materials and the process conditions used to achieve the wafer fusion of respective materials have been reported. [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17] We have investigated the wafer fusion technique and applied it as a technique for the fabrication of novel photonic and optoelectronic devices. [5][6][7][8][9][10][11][12][13] We have proposed and realized three-dimensional photonic crystals, [7][8][9][10] surface-emitting distributed feedback laser diodes 11,12) and two-dimensionally-oscillating surface-emitting laser diodes with a triangular-lattice photonic crystal structure.…”

Interface structure and adhesion of wafer-bonded GaN/GaN and GaN/AlGaN semiconductors

“…5 One of the major challenges in group III nitride semiconductors is the heterogeneous integration of free standing GaN-based devices with dissimilar substrates. [3][4][5][6] Direct wafer bonding has been reported to be an ideal approach to integrate mismatched materials and has been used to fabricate a number of advanced microelectronic or photonic devices. 3,4,6,7 Wafer bonding of GaN and other related semiconductors has been reported by a few research groups, such as GaN/GaAs, 3,4 GaN/InP, 6 and GaN/GaN.…”

“…[3][4][5][6] Direct wafer bonding has been reported to be an ideal approach to integrate mismatched materials and has been used to fabricate a number of advanced microelectronic or photonic devices. 3,4,6,7 Wafer bonding of GaN and other related semiconductors has been reported by a few research groups, such as GaN/GaAs, 3,4 GaN/InP, 6 and GaN/GaN. 7 However, to date, only a little effort has been focused on understanding the correlations among bonding process, wafer surface or interface microstructures, and interface adhesion.…”