AVS 47th International Symposium
    Photonics Tuesday Sessions
       Session PH-TuP

Paper PH-TuP8
Effect of Dry Etching Conditions on Surface Morphology and Optical Properties of GaN Films in Chlorine-Based Inductively Coupled Plasmas

Tuesday, October 3, 2000, 5:30 pm, Room Exhibit Hall C & D

Session: Poster Session
Presenter: Y.B. Hahn, Chonbuk National University, South Korea
Authors: Y.B. Hahn, Chonbuk National University, South Korea
B.-C. Cho, LG Precision Co., Ltd.
Y.-H. Im, Chonbuk National University, South Korea
Correspondent: Click to Email
A parametric study on dry etching of undoped, n- and p-type GaN films has been carried out in a planar type inductively coupled plasma (ICP) system. The effect of etching conditions on surface chemistry, morphology, and optical properties of GaN Films etched in Cl2/Ar discharges was studied in detail using atomic force microscopy (AFM), scanning electron microscope (SEM), and photoluminescence (PL) measurement. The GaN films showed overall similar etching characteristics. Although the surface roughness was dependent on plasma parameters, it was a strong function of dc bias voltage. The surface roughness was relatively independent of the rf power up to 150 W, resulting quite smooth morphology (rms roughness 1.1 - 1.3 nm), while etching at higher chuck powers (> 200 W) produced rougher surface due to increased ion bombardment. Stoichiometry at the etched surface of undoped and p-type GaN films was maintained, indicating equirate removal of component. By contrast n-GaN showed some depletion of nitrogen from the surface. The lattice disorder and point defects were much less generated during the ICP etching than reactive ion etching (RIE). The PL peak of etched p-GaN was somewhat red-shifted from 366 nm to 460 nm, but it showed a strong peak intensity after ICP etching, which was very similar to the result obtained after thermal annealing of as-grown p-GaN films.