کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1688908 | 1011201 | 2012 | 6 صفحه PDF | دانلود رایگان |
GaN mesa etching is investigated using BCl3/Cl2 based inductively coupled plasma at constant ICP/RF powers for HEMT fabrication. The effect of chamber process pressure (5–15 mTorr) and BCl3/Cl2 flow rate ratio >1 on mesa sidewall profile is studied in detail using less complex photoresist mask. Mesa sidewall sharpness varied strongly with chamber pressure and deteriorated at lower pressure ∼5 mTorr. The etched GaN mesas resulted in severely damaged sidewalls with significant sidewall erosion at BCl3/Cl2 ratio of <1, which reduced gradually as BCl3/Cl2 ratio was increased to values >1 mainly due to decreased Cl ion/neutral scattering at the edges. Finally, the smooth and sharp mesa sidewalls with angle of ∼80° and moderate GaN etch rate of ∼1254 Å/min are obtained at BCl3/Cl2 ratio of 2.5:1 and 10 mTorr pressure due to a better balance between physical and chemical components of ICP etching.
► GaN mesa etching is investigated using BCl3/Cl2 based ICP.
► Effect of pressure and BCl3/Cl2 flow rate ratio >1 on mesa sidewall is reported.
► Mesa edge sharpness varied with pressure and deteriorated at low pressure.
► GaN mesa resulted in severely damaged/eroded sidewalls at BCl3/Cl2 ratio <1.
► Smooth/sharp sidewalls with etch rate ∼1254 Å/min are obtained at BCl3/Cl2 ratio of 2.5:1.
Journal: Vacuum - Volume 86, Issue 12, 20 July 2012, Pages 1844–1849