Mechanisms of inductively coupled BCl3-plasma interaction with the GaN surfaceMechanisms of inductively coupled BCl3-plasma interaction with the GaN surface

TL;DR

This paper investigates how BCl3 plasma interacts with GaN surfaces, identifying conditions to prevent polymer formation and optimize etching for better GaN-based transistor contacts.

Contribution

It provides a detailed analysis of plasma parameters and thresholds to control BCl3 plasma interactions with GaN, enabling improved fabrication processes.

Findings

Optimal ion energy range for etching without polymer formation (~32-60 eV)

Numerical modeling of plasma-surface interactions

Mechanistic insights into BCl3 plasma effects on GaN surfaces

Abstract

Consideration is given to inductively coupled BCl3-plasma (ICP) treatment of the GaN surface, which is a promising technique to get the low resistance ohmic contacts in GaN-based transistors. In some cases, BCl3 plasma treatment results in ohmic contact degradation because BClx radicals tend to form a polymer thin film BxCly on the surface. In the present work, the mechanisms of BCl3 plasma interaction with the GaN surface are considered. Threshold ion energies of reactive ion etching for polymer BxCly and semiconductor GaN, respectively, are estimated using numerical plasma modeling. It has been demonstrated that a plasma treatment regime without polymer deposition and reactive etching is possible when an ion energy is in the range ~32-60 eV.