Investigation on the corrosive effect of NH3 during InGaN/GaN multi-quantum well growth in light emitting diodes

J Yang,Z S Liu,J J Zhu,D S Jiang,H Yang,P Chen,F Liang,D G Zhao,X Li,W Liu,L Q Zhang,S T Liu

doi:10.1038/srep44850

Abstract

Three series of samples with different NH3 flow rate are grown and the optical and structural properties are investigated. It is found that apart from a positive effect on keeping a high partial pressure of nitrogen to enhance indium incorporation, NH3 may also play a negative effect on indium incorporation during InGaN growth. Especially, when temperature is relatively high, the hydrogen generated from the dissociation of NH3 may suppress the chemical reaction which produces InN, leading to a reduced indium incorporation efficiency during the InGaN layer growth.

Highlights

Ten InGaN/GaN multi-quantum wells (MQWs) samples were grown by an AIXTRON 3 × 2 in. close-coupled showerhead reactor on c-plane sapphire substrate
The structure of samples consisted of a 2-μm thick Si-doped n-type GaN layer (n = 3 × 1018 cm−3) grown at 1040 °C, a 3-period unintentionally doped InGaN/GaN MQW active region, and a 130-nm thick Mg-doped p-type GaN layer grown at 950 °C
When the NH3 flow rate decreases from 0.75 to 3 slm during InGaN/GaN MQW growth, both of the peak wavelength and intensity increase. When it further increases from 3 to 6 slm, the emission peak wavelength and the peak intensity decrease. It suggests that the indium content or the thickness of InGaN decrease when the NH3 partial pressure is too large or too small during the InGaN layer growth

Summary

Introduction

Ten InGaN/GaN MQW samples were grown by an AIXTRON 3 × 2 in. close-coupled showerhead reactor on c-plane sapphire substrate. Ten InGaN/GaN MQW samples were grown by an AIXTRON 3 × 2 in. The structure of samples consisted of a 2-μm thick Si-doped n-type GaN layer (n = 3 × 1018 cm−3) grown at 1040 °C, a 3-period unintentionally doped InGaN/GaN MQW active region, and a 130-nm thick Mg-doped p-type GaN layer grown at 950 °C. For the growth of InGaN well layers, the Triethylgallium, trimethylindium flow rate and the growth time were kept as constants for all samples, but other conditions may be changed. According to the growth temperature of InGaN/GaN MQWs, the 10 samples can be divided into 2 series, i.e., series I, including samples A, B, C, D, and E, the growth temperature is 720 °C and series II (samples F, G, H, I, and J), their growth temperature is 760 °C, higher than those samples of

Methods

Results

Conclusion