Formation of low-resistance and thermally stable Ohmic contacts to laser lift-off prepared N-polar n-GaN

作者：Deng J.; Chen Z.; Wang S.; Yu F.; Qi S.; Yu T.; Zhang G.

来源：Physica Status Solidi (C) Current Topics in Solid State Physics, 2012, 9(3-4): 527-529.

• Laser lift-off
• N-polar n-GaN
• Ohmic contacts
• Thermal stability

In this paper, the electrical charateristics of Ti/Al and (Ga)Ti/Al contacts to N-polar n-GaN were investigated. Both as-deposited and 800 °C-annealed Ti/Al contacts to N-polar n-GaN exhibited Ohmic behavior. However, the as-deposited Ti/Al Ohmic contacts suffered from electrial degradation even annealed at a low temperature. Based on x-ray photoemission spectroscopy and Auger electron spectroscopy results, this is attributed to the outdiffusion of Ga. And the introduction of Ga metal at the interface could serve as a diffusion barrier to the outdiffusion of Ga atoms from GaN, which improves the performance of the (Ga)Ti/Al Ohmic contacts to N-polar GaN and enhances the thermal stability of contacts.

• 出版日期2012
• 单位人工微结构和介观物理国家重点实验室; 北京大学