HVPE growth of a thick GaN layer on a GaN templated (111) Si substrate

Abstract

The hydride vapour phase epitaxial (HVPE) growth of thick GaN was attempted on a (111) Si substrate. In order to avoid fatal damage to the substrate surface in the HCl ambient and to get a high growth rate, a two-step growth method was adopted; the first low growth rate step with low HCl flow rate followed by a second high growth rate step. As the result, a flat surface of thick GaN was obtained. The full width at half maximum of the photoluminescence spectra at 77 K was as narrow as 17.7 meV.

Uniform growth of GaN on AlN templated (111)Si substrate by HVPE

“…To do this, we made the HVPE growth at 1000 °C for 30 min on a 60 nm thick AlN. In the HVPE, we adopted two step method [11], i.e., in the first step HCl was supplied at 5 cc/min for 15 min and in the second step HCl flow rate was increased to 30 cc/min for 15 min. The thickness of the GaN obtained was 8.5 µm.…”

“…The cracking shown in Fig. 6 is due to the thermal stress given by the cooling process after the growth, which will be avoided by other means [2,[11][12][13].…”

HVPE growth of semi-polar (112¯2)GaN on GaN template (113)Si substrate

“…3(a1)-(a4) show the spectra obtained on samples grown for 105 min at different temperatures, and substrate even at a high temperature of 1030 1C [11]. Moreover, the yellow band at 550 nm (not shown in the figure) was three orders of magnitude weak as compared to the DBE peak intensity.…”

ELECTRICAL RESISTANCE OF CRACK-FREE GaN/AlN HETEROSTRUCTURE GROWN ON Si(111)

“…Obviously, curves have asymmetric non-linear behavior typical to a heterojunction diode because of the conduction band offset. 7 The current should be determined by the transport of electrons in any case.…”

“…Experimentally, the order of differential resistance magnitude was nearly a constant in the voltage range of 1.0 to 3.0 V. From the study by Nishimura et al, they found that the presence of the thin AlN layer should be responsible for the uniform growth of crack-free GaN on Si(111). 7 Because of the AlN layer, the current distribution is uniform very near the heterointerface. Thus, the apparent electrical resistance at a bias voltage is determined by the sum of the currents flowing through the thin AlN regions at the bias voltage.…”