摘要
Ge材料中n型杂质激活的电子浓度偏低,以及费米能级钉扎效应导致的金属与n型Ge接触电子势垒高度偏大,使金属与n型Ge接触电阻较大。基于Ge的材料特性,分析了缺陷对杂质浓度以及费米能级钉扎对电子势垒高度的影响;综述了提高Ge材料中n型掺杂电子浓度的方法,如激光退火、磷和锑共掺、循环离子注入/退火、氟钝化等;讨论了降低金属与n型Ge接触电子势垒高度的途径,即插入薄的界面层形成金属-界面层-Ge接触。电子浓度的提高,以及电子势垒高度的降低,有效地减小了金属与n型Ge接触电阻。
As the low electrically active concentration for n-type dopant in Ge material,and a large barrier height for the metal contact with the n-type Ge electrons caused by the strong Fermi level pinning,the contact resistance between metal and n-type Ge is bigger. Based on the material properties of Ge,the effects of the defects on the doping concentration and impact of the Fermi level pinning on the barrier height are analyzed. Methods of improving the electron concentration in Ge n-type doping are reviewed,such as laser annealing,co-doping of phosphorus and antimony,multiple implantation / multiple annealing and fluorine vacancy passivation. The approach that decreases the barrier height of metal-Ge contact such as inserting an ultrathin interfacial layer( IL) to form the metal-IL-Ge contact is discussed. The contact resistance between metal and n-type Ge is effectively reduced due to the improved electron concentration and the decreased barrier height.
出处
《半导体技术》
CAS
CSCD
北大核心
2016年第1期10-15,31,共7页
Semiconductor Technology
基金
广东省自然科学基金资助项目(S2013010011833)
深圳市科技计划资助项目(JCYJ20120821162230170)
广东省高等学校优秀青年教师资助项目(Yq2014123)