Near-Room-Temperature Selective Oxidation on GaAs Using Photoresist as a Mask

Abstract

Selective oxidation on GaAs operated at near room temperature, by a liquid phase chemically enhanced method using photoresist as a mask, is proposed and demonstrated. Because of the low temperature and electroless features of the oxidation method, the process is simple, economic and reliable. Good electrical insulating properties comparable with those of thermal oxide have been obtained. According to the results of X-ray photoelectron spectroscopy, the chemistry of the oxide surface is stable after thermal annealing. The thermal stability shows the potential for device fabrication.

Effect of crystal orientation and doping on the activation energy for GaAs oxide growth by liquid phase method

“…3 Hence, it is convenient and reliable to use a photoresist mask to achieve selective-area oxidation by the LPCEO technique. 4 Neither electric potential nor assisted energy source ͑plasma or photo͒ is applied in the LPCEO technique. As compared with extensive research efforts such as high-pressure 5 or photoenhanced techniques, 6-8 the LPCEO method is quite simple and economic.…”

Effects of pH Values on the Kinetics of Liquid‐Phase Chemical‐Enhanced Oxidation of GaAs

“…Featureless and uniform oxide films can be grown at a relatively high oxidation rate (ϳ1000 Å within an hour). In addition, good insulating and thermally stable LPCEO oxide films have been demonstrated, 14 and device applications to GaAs metal-oxide semiconductor field effect transistors (MOSFETs) have also been realized. 15 Interesting properties of the oxide growth kinetics of the LPCEO technique have been found, such as an optimum pH window for oxide growth, increase of oxide refractive index, a relatively high oxidation rate at low temperature, and etchback of oxide thickness.…”

Liquid Phase Oxidation on GaAs-based Transistor Applications

“…Previous studies have reported the details of the oxidation system [1][2][3][4][5][6]. For MOS-HEMT, device isolation was accomplished by mesa wet etching down to the buffer layer.…”

“…However, the sulfide is easily evaporated, and hence, the degradation of device performance is expected. Recently, an efficient, low-temperature, and low-cost approach to grow native oxide layers on GaAs-based wafers by means of liquid phase oxidation (LPO) has been demonstrated [1][2][3][4][5][6][7][8][9][10][11][12][13][14][15][16][17][18][19][20]. In this paper, a native oxide on GaAs-based materials by the LPO and its applications to HEMT and HBT will be demonstrated and discussed.…”