Tuning of Schottky Barrier Height at NiSi/Si Contact by Combining Dual Implantation of Boron and Aluminum and Microwave Annealing

Feng Sun; Chen Li; Chaochao Fu; Xiangbiao Zhou; Jun Luo; Wei Zou; Zhi-Jun Qiu; Dongping Wu

doi:10.3390/ma11040471

Tuning of Schottky Barrier Height at NiSi/Si Contact by Combining Dual Implantation of Boron and Aluminum and Microwave Annealing

Materials (Basel). 2018 Mar 22;11(4):471. doi: 10.3390/ma11040471.

Authors

Feng Sun¹, Chen Li², Chaochao Fu³, Xiangbiao Zhou⁴, Jun Luo⁵, Wei Zou⁶, Zhi-Jun Qiu⁷, Dongping Wu⁸

Affiliations

¹ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 15210720083@fudan.edu.cn.
² State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 16110720066@fudan.edu.cn.
³ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 12110720010@fudan.edu.cn.
⁴ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. 12212020051@fudan.edu.cn.
⁵ Key Laboratory of Microelectronic Devices and Integrated Technology, Institute of Microelectronics, Chinese Academy of Science, Beijing 100029, China. luojun@ime.ac.cn.
⁶ Process Application, Applied Materials, Inc., Gloucester, MA 01930, USA. Wei_Zou@amat.com.
⁷ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. zjqiu@fudan.edu.cn.
⁸ State Key Laboratory of ASIC and System, Fudan University, Shanghai 200433, China. dongpingwu@fudan.edu.cn.

Abstract

Dopant-segregated source/drain contacts in a p-channel Schottky-barrier metal-oxide semiconductor field-effect transistor (SB-MOSFET) require further hole Schottky barrier height (SBH) regulation toward sub-0.1 eV levels to improve their competitiveness with conventional field-effect transistors. Because of the solubility limits of dopants in silicon, the requirements for effective hole SBH reduction with dopant segregation cannot be satisfied using mono-implantation. In this study, we demonstrate a potential solution for further SBH tuning by implementing the dual implantation of boron (B) and aluminum (Al) in combination with microwave annealing (MWA). By using such a method, not only has the lowest hole SBH ever with 0.07 eV in NiSi/n-Si contacts been realized, but also the annealing duration of MWA was sharply reduced to 60 s. Moreover, we investigated the SBH tuning mechanisms of the dual-implanted diodes with microwave annealing, including the dopant segregation, activation effect, and dual-barrier tuning effect of Al. With the selection of appropriate implantation conditions, the dual implantation of B and Al combined with the MWA technique shows promise for the fabrication of future p-channel SB-MOSFETs with a lower thermal budget.

Keywords: SB-MOSFET; Schottky barrier height; dopant segregation; dual implantation; microwave annealing.