碳摻雜矽奈米線全包覆式閘極元件技術研究

Abstract

本計畫主要目標是開發高性能的全包覆閘極(GAA)元件，並對GAA元件的傳導與可 靠度進行分析。為製作GAA元件，必須先開發矽奈米線製作技術，以及奈米線接面、奈 米線金屬矽化物等技術。由於奈米線元件的接觸面積極小，接觸阻抗對元件性能影響至 鉅，本計畫考慮利用碳摻雜減緩雜質擴散以製作淺接面並減少植入缺陷，也利用碳摻雜 產生的伸張應力，縮小能隙，期能降低接觸阻抗。本計畫擬進一步結合鍺摻雜，使能隙 更有效縮小，並提高載子活化率，得到更低的接觸阻抗。因此，第一年度將進行碳植入 對晶格應力的研究，也探討碳植入以及鍺植入對雜質擴散、淺接面特性、接觸阻抗的影 響。於第二年度開發10nm以下的矽奈米線製作技術，探討金屬矽化物奈米線的反應機 制，以及碳摻雜和鍺摻雜對奈米線接面特性以及接觸阻抗的影響。第二年度也將整合各 製程模組，製作具有高介電常數介電質、金屬閘極、金屬矽化物源極/汲極的GAA元件。 第三年度則著力於GAA元件的基本特性、載子遷移、電流傳導分析，並進行可靠度評估。

The final object of the project is to develop a high-performance gate-all-around (GAA) device and to investigate its current transport mechanism and reliability issue. To fabricate GAA devices, Si nano-wires (SiNW) preparation technology must be developed at first. The SiNW junction technology as well as the SiNW silicide/Si contact technology must be developed simultaneously. Since the contact area of a SiNW silicide/Si contact is quite small, the contact resistance plays important role on the device performance. In this project, we proposed to utilize carbon incorporation to suppress dopant diffusion and to reduce ion-implantation induced secondary defects. We also want to utilize the carbon incorporation induced strain to reduce the Si bandgap, which in turn can reduce contact resistance. Germanium incorporation can be implemented simultaneously to further reduce Si bandgap and increase dopant activation percentage in order to reduce contact resistance further. Therefore, we will study the stress induced by carbon incorporation in the first year. The influence of carbon and germanium incorporation on shallow junction and contact resistance will also be studied. In the second year, SiNW with diameter less than 10nm will be fabricated. Ni-silicide formation along the SiNW and the influence of carbon and germanium incorporation on the SiNW shallow junction and contact properties will be investigated. We will also integrate high dielectric constant dielectric, metal gate, silicided source/drain, as well as modified Schottky barrier junction to realize high performance GAA devices. The GAA devices will be characterized in the third year. The basic device parametes will be measured. The volume inversion of the SiNW and the effective carrier mobility will be extracted. The current transport mechanism and reliability issues will be investigated deeply.