Strain and Materials Engineering for the I-MOS Transistor With an Elevated Impact-Ionization Region
Strain and Materials Engineering for the I-MOS Transistor With an Elevated Impact-Ionization Region
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DOI：
10.1109/ted.2007.904988
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发表时间：
2007-09
影响因子：
3.1
通讯作者：
E. Toh;G.H. Wang;L. Chan;G. Lo;G. Samudra;Y. Yeo
中科院分区：
文献类型：
--
作者：
E. Toh;G.H. Wang;L. Chan;G. Lo;G. Samudra;Y. Yeo
具有升高的冲击电离区（I-region）或L形冲击电离MOS（LI-MOS）晶体管的冲击电离MOS（I-MOS）晶体管已经被提出作为通过应变和材料工程来增强性能的各种I-MOS结构中的有希望的候选者。升高的I区允许引入新材料以引起应变和带隙的减小，从而增加碰撞电离活性。此外，LI-MOS结构更紧凑，并且与传统CMOS工艺兼容。在本文中，我们讨论和探索的应变和带隙的碰撞电离载流子的产生的关系和影响。通过模拟和实验研究了Si抬高源/漏（RSD）、Si_（1-y）Cy RSD和Si_（1-x）Gex RSD的Si n沟道I-MOS晶体管。三种I-MOS晶体管结构在室温下均具有良好的亚阈值摆幅，亚阈值摆幅小于5 mV/dec。与未应变的I-MOS与Si RSD相比，应变工程I-MOS与Si 0.99C0.01 RSD在60 nm的栅极长度处的导通状态电流和最大导通电流都表现出两倍的增强。对于具有Si0.75Ge0.25 RSD的材料或带隙工程I-MOS，观察到约三倍的更大增强。此外，更低的击穿电压和增强的击穿特性都实现了应变和材料工程的I-MOS晶体管。
An impact-ionization MOS (I-MOS) transistor with an elevated impact-ionization region (I-region) or the L-shaped I-MOS (LI-MOS) transistor has been proposed as a promising candidate among various I-MOS structures for enhanced performance through strain and materials engineering. The elevated I-region allows for the incorporation of novel materials to induce strain and reduction in the bandgap to increase the impact- ionization activity. In addition, the LI-MOS structure is more compact and compatible with conventional CMOS processes. In this paper, we discuss and explore the relationship and impact of strain and bandgap on the generation of impact-ionization carriers. Si n-channel I-MOS transistors with Si raised source/drain (RSD), Si1-yCy RSD, and Si1-xGex RSD were studied and explored through simulations and experiments. An excellent subthreshold swing of sub-5 mV/dec at room temperature is demonstrated for the three I-MOS transistor structures. Compared to an unstrained I-MOS with Si RSD, strain-engineered I-MOS with Si0.99C0.01 RSD exhibits a twofold enhancement in both ON-state current and maximum transconductance at a gate length of 60 nm. For materials- or bandgap-engineered I-MOS with Sio.75Ge0.25 RSD, a greater enhancement of approximately three times is observed. In addition, a lower breakdown voltage and enhanced breakdown characteristics are achieved with both strain- and materials-engineered I-MOS transistors.