AVS 46th International Symposium
    Electronic Materials and Processing Division Monday Sessions
       Session EM-MoA

Paper EM-MoA9
In-Situ Plasmas Diagnostics for the Etchings of AlGaN/GaN Heterostructures

Monday, October 25, 1999, 4:40 pm, Room 608

Session: Nitride Processing and Characterization
Presenter: G.Y. Yeom, SungKyunKwan University, South Korea
Authors: H.S. Kim, SungKyunKwan University, South Korea
G.Y. Yeom, SungKyunKwan University, South Korea
J.W. Lee, Samsung Advanced Institute of Technology, South Korea
T.I. Kim, Samsung Advanced Institute of Technology, South Korea
Correspondent: Click to Email
AlGaN/GaN heterostructures have been widely used to form the various devices such as field effect transistor(FET), photodiode, bipolar transistor(BT), light emitting diode(LED), and laser diodes(LD). High etch rate of the full structure and reliable etch end point detection are required to form a device by dry etching. In the previous work, plasma characteristics during the GaN etching have been reported using a quadrupole mass spectrometry (QMS) and an optical emission spectroscopy (OES) and an etch mechanism of GaN by Cl@sub2@-based plasmas has been proposed from the detection of etch products. In this study, GaN, AlGaN, and AlN grown on sapphire, and AlGaN/GaN heterostructures were etched using inductively coupled Cl@sub2@/BCl@sub3@ plasmas. Etch rates of GaN were higher than those of AlGaN for the Cl@sub2@ rich plasmas. The increase of Al composition in the AlGaN decreased the etch rate of heterostructures regardless of plasma conditions. These differences in the etch rate could be reduced by the increase of BCl@sub3@ to Cl@sub2@ gas and the decrease of the pressure. The plasma characteristics and their relations to etch rates were investigated using in-situ plasma diagnostics such as QMS and OES. Finally, the etch end point of an AlGaN/GaN heterostructure and a LD structure could be estimated by the monitoring an Al-containing optical emission line. Detailed data will be shown in the presentation.