Very Low Ohmic Contact Resistance through an AlGaN Etch-Stop in Nitrogen-Polar GaN-Based High Electron Mobility Transistors
Very Low Ohmic Contact Resistance through an AlGaN Etch-Stop in Nitrogen-Polar GaN-Based High Electron Mobility Transistors
复制标题
通过氮极性 GaN 基高电子迁移率晶体管中的 AlGaN 蚀刻停止层实现极低的欧姆接触电阻
DOI：
10.1143/jjap.49.021005
复制
发表时间：
2010
影响因子：
1.5
通讯作者：
U. Mishra
中科院分区：
文献类型：
--
作者：
Nidhi Brown;S. Keller;U. Mishra
超低欧姆接触电阻为0.1 Ω mm，这是利用n极氮化镓基高电子迁移率晶体管（HEMTs）迈向深凹槽结构的一步。为了获得光滑可靠的栅极凹槽，研究了一种AlGaN刻蚀层。然而，由于反向极化，AlGaN会产生极化诱导的肖特基势垒，从而阻止欧姆通过蚀刻阻与通道接触。在这项工作中，我们提出了一种新的方法，通过GaN帽和AlGaN蚀刻器蚀刻来接触二维电子气体（2DEG），以消除金属的屏障和角蒸发，从而实现侧合金化，从而使n极GaN 2DEG获得0.1 Ω mm的极低欧姆接触电阻。这一结果是最先进的合金接触实现氮化镓基2DEG。
Ultra-low ohmic contact resistance of 0.1 Ω mm has been obtained as a step towards a deep-recess structure using N-polar GaN-based high electron mobility transistors (HEMTs). An AlGaN etchstop layer was investigated to obtain smooth and reliable gate recess. However due to reverse polarization, AlGaN results in a polarization-induced Schottky barrier which prevents ohmic contact to the channel through the etchstop. In this work, we have proposed a novel methodology to contact the two-dimensional electron gas (2DEG) by etching through the GaN cap and the AlGaN etchstop to eliminate the barrier and angular-evaporation of metals to achieve side-alloying resulting in very low ohmic contact resistance of 0.1 Ω mm achieved to N-polar GaN 2DEG. This result is state-of-the-art for alloyed contacts achieved to GaN-based 2DEG.