Metalorganic Vapor Phase Epitaxy of GaN, InN, and AlGaN Using 1,1-Dimethylhydrazine as a Nitrogen Source

Abstract

GaN, InN, and AlGaN were grown by metalorganic vapor phase epitaxy (MOVPE) using 1,1-dimethylhydrazine (DMHy) as a nitrogen source instead of ammonia. GaN with atomically flat surfaces and dislocation densities comparable to those in GaN grown with ammonia was obtained under a growth temperature of 925 C and a V/III ratio of 25, which are much lower than those in ammonia-MOVPE. Carbon incorporation from the source precursors is avoidable in hydrogen growth ambients but is considerable in inert ambients. For InN, the (inert) N 2 ambient also results in carbon-related deposits, while the H 2 ambient enables InN to be grown but causes In segregation. For AlGaN, the entire Al solid composition can be attained by growth under atmospheric pressure at 925 C. Although the edge dislocation density increases with increasing Al composition, the screw dislocation density is as low as a value on the order of 10 6 cm À2 . These findings strongly suggest that 1,1-DMHy is a promising alternative to ammonia for the growth of GaN and AlGaN but is rather unsuitable for the growth of In-containing alloys.

MOVPE growth of InN films using 1,1-dimethylhydrazine as a nitrogen precursor

“…efficiently. This result is different from a previous report [7] which shows that InN does not grow using DMHy in N 2 but in H 2 . This discrepancy may be attributed to the difference in growth pressure, i.e.…”

“…low-pressure growth in this study and atmospheric growth in Ref. [7]. Moreover, the parasitic reaction is intentionally suppressed in this study, but not in Ref.…”

“…Moreover, the parasitic reaction is intentionally suppressed in this study, but not in Ref. [7]. In the following, all the results are those using the N 2 carrier.…”

Alternative precursors for MOVPE growth of InN and GaN at low temperature

“…In some cases, however, metallic In deposit was obtained on the surface as confirmed by the XRD yÀ2y scan and AFM imaging prior and after HCl treatment, known to dissolves In metal. This last result was also obtained by Funato et al [12].…”

Metalorganic vapor phase epitaxy of InN on GaN using tertiary-butylhydrazine as nitrogen source

“…Experiments of InN growth on GaN using 1,1-DMHy with nitrogen (N 2 ) and hydrogen (H 2 ) as carrier gases were performed, but contrary to the predictions only metallic indium droplets were grown [4]. 1,1-DMHy decomposes above 370 3 C by bond cleavage and to a lower degree by asymmetric transfer of the CH 3 group into (CH 3 ) 2 N and NH 2 .…”