Analysis of the ohmic contacts of Ti/Al/Ni/Au to AlGaN/GaN HEMTs by the multi-step annealing process

作者：Yan Wei^*; Zhang Renping; Du Yandong; Han Weihua; Yang Fuhua

来源：Chinese Journal of Semiconductors, 2012, 33(6).

DOI：10.1088/1674-4926/33/6/064005

• AlGaN
• AlGaN/gaN
• AlGaN/GaN HEMTs
• Annealing process
• Annealing temperatures
• Experimental methods
• GaN
• Multi-step
• Rapid thermal annealing process
• Specific contact resistances
• Ti/Al/Ni/Au

The multi-step rapid thermal annealing process of Ti/Al/Ni/Au can make good ohmic contacts with both low contact resistance and smooth surface morphology for AlGaN/GaN HEMTs. In this work, the mechanism of the multi-step annealing process is analyzed in detail by specific experimental methods. The experimental results show that annealing temperature and time are very important parameters when optimizing the Ti/Al layer for lower resistance and the Ni/Au layer for smooth surface morphology. It is very important for good ohmic contacts to balance the rate of various reactions by adjusting the annealing temperature and time. We obtained a minimum specific contact resistance of 3.22 × 10 -7 Ω&middotcm2 on the un-doped AlGaN/GaN structure with an optimized multi-step annealing process.

• 出版日期2012