Preparation of n-type InP substrates by Vertical Boat growth

Abstract

N-type InP substrates have been manufactured using Vertical Boat (VB) Technique. In this paper, we will report improvement in etch-pit density (EPD) distribution for 2-inch S-doped, 2-inch-Sn-doped and 4-inch S-doped VB InP substrates in comparison to VCZ (SEI's proprietary Vapor pressure controlled Czochralski) InP substrates. EPD of 2-inch S-doped VB InP substrate is lower than SEI's standard EPD specification 500 cm−2 from seed-end to tail-end. Etch-pit densities are drastically reduced compared to those of VCZ with carrier concentration ranging from 3E18 cm−3 to 4E18 cm−3. The VB technique enables a decrease in slip-line defects of S-doped InP with low carrier concentration range. Average lot size of 2-inch S-doped VB InP is almost 1.4 times larger than that of VCZ InP. 4-inch S-doped VB substrates and 2-inch Sn-doped VB substrates are also manufactured using the VB technique.