SIMS, photoluminescence, and hall measurements analysis of growth parameters influence on dopant concentration in PHEMT structures grown by movpe

摘要

The control of intentional doping incorporation during the growth of Pseudomorphic High Electron Mobility Transistor (PHEMT) structures is very important to have a good reproducibility of device performances. The PHEMT samples were grown by Low Pressure-Metalorganic Vapor Phase Epitaxy (LP-MOVPE) technique using a substrate temperature ranging from 645 deg C up to 665 deg C and a growth pressure ranging from 23 mbar up to 31 mbar. Si incorporation inside the PHEMT structure was measured by means of Secondary Ion Mass Spectrometry (SIMS) depth profile while Low Temperature Photoluminescence (LT-PL) was used to obtain the 2 Dimensional Electron Gas (2DEG) density inside the channel by fitting the lineshape of photoluminescence spectrum. Hall effect measurement was used to obtain the electron concentration. In conclusion, the comparative analysis of the experimental results allows as to obtain futher information about the Si electrical activation both in the cap and in the delta layer.