Metalorganic Chemical Vapor Deposition Gallium Nitride with Fast Growth Rate for Vertical Power Device Applications

Abstract

The development of high‐quality gallium nitride (GaN) epitaxy with thick drift layer, low controllable doping, and high mobility is key for vertical high‐power devices. Herein, the effect of increasing trimethylgallium (TMGa) molar flow rate on the growth rate, impurity incorporation, charge compensation, surface morphology, and carrier mobility is systematically studied. An optimized metalorganic chemical vapor deposition GaN growth condition with a typical growth rate of 2 μm h−1 is used as the baseline. With significant suppression of background Si, other impurity concentrations, and a precise control of the doping precursor SiH4 flow, an electron concentration as low as 4 × 1015 cm−3 in n−‐GaN is achieved. Through increasing the TMGa flow rate, the GaN growth rate is increased to 5.2 μm h−1. Secondary ion mass spectroscopy results show that the background H, O, and Mg remain below detection limit, but C level is increased to 2 × 1016 cm−3. GaN growth on Mn‐doped semi‐insulating GaN substrate is performed to probe the transport properties of film with low dislocation densities. Hall measurement shows that an electron mobility decreases from 852 to 604 cm2 V−1 s−1 as the growth rate increases. Results from this work reveal the challenge and guidance for achieving GaN vertical high power devices.

Laser‐Assisted Metal–Organic Chemical Vapor Deposition of Gallium Nitride

“…This factor can be considered from the GaN film GR, considering that [C] is positively related to the GaN GR. [14,32] Therefore, [C] is plotted as a function of the input V/III ratio/ GR from this work as compared with the data reported from the literature, as shown in Figure 7b. The dashed line indicates the slope of [C] versus input V/III ratio/GR for the best reported data, considering that [C] is reversely proportional to V/III ratio and 1/GR.…”

“…As compared with previous reports, the LA-MOCVD GaN growth achieved low [C] at mid-10 15 cm À3 with the lowest input V/III ratio/GR. versus input V/III ratio of MOCVD GaN from the literature [2,9,13,14,32,[35][36][37][38][39][40] and from this study. b) [C] versus input V/III ratio/GR of MOCVD GaN from the literature [2,9,13,14,32,37,39,40] and from this study.…”

“…The GRs of conventional MOCVD and LA-MOCVD samples were 5.2 and 4.5 μm h À1 , respectively. b) Hall mobility versus electron concentration of GaN grown with HVPE, MBE, and MOCVD on various substrates from the literature,[2,3,32,35,[41][42][43][44][45] and LA-MOCVD samples from this study. The reported GRs from the literature are listed in the table.…”

Design and development of 1.5 kV vertical GaN pn diodes on HVPE substrate

“…Secondary ion mass spectroscopy (SIMS), Deep level transient spectroscopy (DLTS)/deep level optical spectroscopy (DLOS) and capacitance-voltage (CV) measurements confirmed the low compensation level at low-to mid-10 15 cm −3 level, which is mainly contributed by the background carbon (C). Detailed material characterization can be found in [33]. Room temperature carrier transport properties were measured by Van-der-Pauw Hall configuration using the Ecopia HMS-3000 Hall effect system.…”

The Structural and Optical Investigation of Grown GaN Film on Porous Silicon Substrate Prepared by PLD

“…The techniques used for GaN film preparation and the chosen parameters significantly impact the optical properties and electrical characteristics of GaN film [13,14]. Therefore, in recent years, multiple procedures, including molecular beam epitaxy, metalorganic chemical vapour deposition, and pulse laser deposition (PLD), have been employed to produce better -quality thinfilm GaN [15,16]. Moreover, each technique has advantages for growing GaN thin films at high vacuum levels, a faster growth rate, and low substrate temperature [17].…”