Suppression of Boron transient enhanced diffusion in Silicon by Carbon implant

• Main Authors: Roy Chang, 張榮峰
• Other Authors: 林正平
• Format: Others
• Language: en_US
• Published: 2005
• Online Access: http://ndltd.ncl.edu.tw/handle/93121537367403939680

碩士 === 長庚大學 === 電子工程研究所 === 93 === In shallow junction transistors with boron-doped channels, transient enhanced diffusion(TED) is a key contributor to boron profile broadening. The role of carbon in silicon as a sink for self-interstitials, I have explored the feasibility of using carbon in the active region to retard boron diffusion during high thermal process. A highly effective suppression of TED of boron was observeeed providing more than an order of magnitude reduction in boron diffusivity. MOSFET’s with carbon and boron implanted channels have been fabricated to evaluate the impact of carbon on the electrical properties of Si. Boron diffusion, activation, and critical electrical parameters including subthreshold swing, threshold voltage, off-state leakage current, and channel mobility have been evaluated as a function of the carbon dose. Base on secondary ion mass spectrometry(SIMS) results, boron diffusivity is obviously reduced by carbon ion implantation. Diffusion Length is also decreased in our observation. However higher junction leakage current and contact resistance need to be concerned in this work..