,Formation of the intermediate semiconductor layer for the Ohmic contact to silicon carbide using Ge

• 作 者: Guo Hui Wang Yue-Hu Zhang Yu-Ming Qiao Da-Yong Zhang Yi-Men
• 机 构: Microelectronics School, Xidian University, Xi’an 710071, China and Key Lab of Wide Band-Gap Semicon
• 出 处: 中国物理B（英文版）
• 发表日期: 2009年10期
• 关键词: SiC Ohmic contact Ge ion implantation intermediate semiconductor layer

By formation of an intermediate semiconductor layer(ISL)with a narrow band gap at the metallic contact/SiCinterface,this paper realises a new method to fabricate the low-resistance Ohmic contacts for SiC.An array of transferlength method(TLM)test pattes is formed on N-wells created by P+ion implantation into Si-faced p-type 4H-SiC epilayer.The ISL of nickel-metal Clhmic contacts to n-tyDe 4H-SiC could be formed by using Germanium ionimplantation intO SiC.The specific contact resistance Pc as loW as 4.23×10-5 Ω.cm2 is achieved after annealing inN2 at 800℃ for 3 min,which iS much lower than that(＞900℃)in the typical SiC metallisation process.Thesheet resistance Rsh of the implanted layers is 1.5 kΩ/□.The technique for converting photoresist into nanocrystallinegraphite is used to protect the SiC surface in the annealing after Ge+ion implantations.