鍺通道電晶體及金氧半電容之應變效應探討

Germanium Channel MOSFETs and Strain-Induced effects on Silicon MOS Capacitor

曾志宏(Chih-Hung Tseng)

指導教授 ： 劉致為

國立臺灣大學/電機資訊學院/電子工程學研究所/碩士(2006年)

https://doi.org/10.6342/NTU.2006.10102

摘要

本論文中，我們探討場效電晶體技術發展中三種重要的議題：鍺通道蕭基位能障電晶體、高介電常數介電質、應力效應。藉由在矽基板上成長一層磊晶鍺，並在鍺上面成長矽保護層，如此的結構可實現鍺通道；而源/汲極則使用鉑金屬來形成P型電晶體的蕭基位能障。我們使用一道光罩的製程來製作元件，並且在實驗上有一些初步的成果。這邊提供一些有用的概念以及參數的調整使製程的實行能夠更加完善。
Hafnium oxide (HfO2) 和hafnium-silicate (HfxSi1-xO2) 是我們用來研究高介電常數介電質電性研究的兩種材料。他們都可滿足在與SiO2相同等效氧化層厚度下，有較低的漏電流。介電常數隨著Hafnium濃度比例的增加而增加。另外，我們也成長HfO2在矽/鍺/矽基板上，從C-V的量測中可發現有一反曲點的存在，說明了在磊晶鍺量子井中有電洞被限制住。
我們建構了一種機制來施加外在的伸展應力。在應力之下，量測金氧半電容元件的平帶電壓的移動，可以觀察到矽的導電帶往下移動以及價電帶往上移動。

關鍵字

鍺 ； 場效電晶體 ； 高介電質材料 ； 應變力

並列摘要

In this thesis, three important topics for discussion for advancement of metal-oxide-semiconductor field-effect transistors (MOSFETs) technology were studied, which are germanium channel Schottky-barrier MOSFETs, high-k dielectrics, and strain-induced effects.
Germanium channel was implemented by using Si-cap/epi-Ge/Si substrate and Platinum (Pt) was deposited as metal Schottky-barrier source/drain of p-type MOSFETs. The devices were fabricated by one mask process and there were some elementary results in experiment. Some useful concepts and adjustments were also provided to improve the performance of the process.
Hafnium oxide (HfO2) and hafnium-silicate (HfxSi1-xO2) were the materials for research about the electrical properties of high-k dielectrics. They fill the request about lower leakage current at the same equivalent oxide thickness (EOT) as compared with SiO2. The dielectric constant increases with the increase of Hf concentration. The C-V curve of growing HfO2 on the Si-cap/epi-Ge/Si substrate shows a shoulder to prove holes confinement in epi-Ge quantum well.
We brought up a mechanical setup to apply external tensile strain. By measuring flat-band voltage shift of MOS capacitor under strain, the reduction of conduction band edge and the upward shift of valence band edge were obtained.

並列關鍵字

Germanium ； MOSFET ； high-k ； strain

參考文獻

chapter 1

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