Boron trichloride plasma treatment effect on ohmic contact resistance formed on GaN-based epitaxial structure

16th Russian Youth Conference on Physics of Semiconductors and Nanostructures, Opto- and Nanoelectronics

Kobelev, A.A.^1 ; Barsukov, Yu V^2 ; Andrianov, N.A.^3 ; Smirnov, A.S.^1

St. Petersburg Polytechnic University, 29 Polytechnicheskaya str., St.-Petersburg

195251, Russia^1

Coddan Technologies LLC, 22 Beloostrovskaya str., St.-Petersburg

197342, Russia^2

Svetlana-Rost JSC, 27 Engels ave., St.-Petersburg

194156, Russia^3

关键词: Boron trichloride;    Discharge power;    Elemental compositions;    Epitaxial structure;    GaN cap layers;    Inductively coupled-plasma reactive ion etching;    Plasma treatment;    Recess etching;   

Others  :  https://iopscience.iop.org/article/10.1088/1742-6596/586/1/012013/pdf
DOI  :  10.1088/1742-6596/586/1/012013

来源: IOP

【 摘 要 】

A BCl3plasma treatment effect on GaN surface and reduction of ohmic contact resistance in GaN/AlGaN epitaxial structure with a GaN cap layer has been studied. The BCl3plasma treatment was carried out by an inductively coupled plasma reactive ion etching (ICP RIE) system under conditions of low discharge power with zero external bias controlling power to prevent any recess etching of the GaN cap layer. The measured average contact resistances with and without plasma treatment were 1.8×10-5and 1.05×10-5Ω·cm2respectively. To study the BCl3plasma treatment effect on GaN surface and explain the increasing of contact resistance, the elemental composition of GaN surface was measured using x-ray photoelectron spectroscopy. It was found that a Bx-Clylayer covered the GaN surface after the BCl3plasma treatment. This can indicate that ion bombardment from plasma is inefficient to prevent deposition of BClxradicals on the GaN cap layer surface and subsequent formation of the Bx-Clylayer which is responsible for increase of ohmic contact resistance after the BCl3plasma treatment.