A tunnel field-effect transistor(TFET) is proposed by combining various advantages together, such as non-uniform gate-oxide layer, hetero-gate-dielectric(HGD), and dual-material control-gate(DMCG) technology. The effe...A tunnel field-effect transistor(TFET) is proposed by combining various advantages together, such as non-uniform gate-oxide layer, hetero-gate-dielectric(HGD), and dual-material control-gate(DMCG) technology. The effects of the length of non-uniform gate-oxide layer and dual-material control-gate on the on-state, off-state, and ambipolar currents are investigated. In addition, radio-frequency performance is studied in terms of gain bandwidth product, cut-off frequency,transit time, and transconductance frequency product. Moreover, the length of non-uniform gate-oxide layer and dualmaterial control-gate are optimized to improve the on-off current ratio and radio-frequency performances as well as the suppression of ambipolar current. All results demonstrate that the proposed device not only suppresses ambipolar current but also improves radio-frequency performance compared with the conventional DMCG TFET, which makes the proposed device a better application prospect in the advanced integrated circuits.展开更多
文摘随着半导体器件工艺尺寸不断缩小,栅氧化层的厚度已接近极限,实际生产中栅氧完整性(gate oxide integrity,GOI)问题越来越凸现.本文主要研究由于内电介质层(internal dielectric layer,ILD)沉积中的等离子体损伤导致栅氧化层工艺失效问题.采用不同沉积方式对ILD沉积,发现高密度等离子体(high density plasma,HDP)化学气相沉积过程中具有较重的等离子体,会降低器件的栅氧可靠性.HDP沉积过程中采用循环沉积-刻蚀-沉积来实现对所有填充结构轮廓的调整,实验结果发现降低沉积-刻蚀循环次数可以有效改善对栅氧等离子体损伤,但其填充效果会降低.采用高深宽比沉积工艺(high aspect ratio process,HARP)对栅氧等离子体损伤较小.由于受ILD轮廓问题影响,纯HARP填充工艺效果不佳.本文针对特殊的填充结构提出采用HDP与HARP结合的方式同时解决栅氧等离子体损伤及填充效果不佳的问题.
基金Project supported by the University Natural Science Research Key Project of Anhui Province,China(Grant No.KJ2017A502)the Introduced Talent Project of Anhui Science and Technology University,China(Grant No.DQYJ201603)+1 种基金the Excellent Talents Supporting Project of Colleges and Universities,China(Grant No.gxyq2018048)the Innovation and Entrepreneurship Training Program for College Students,China(Grant No.2018S10879052)
文摘A tunnel field-effect transistor(TFET) is proposed by combining various advantages together, such as non-uniform gate-oxide layer, hetero-gate-dielectric(HGD), and dual-material control-gate(DMCG) technology. The effects of the length of non-uniform gate-oxide layer and dual-material control-gate on the on-state, off-state, and ambipolar currents are investigated. In addition, radio-frequency performance is studied in terms of gain bandwidth product, cut-off frequency,transit time, and transconductance frequency product. Moreover, the length of non-uniform gate-oxide layer and dualmaterial control-gate are optimized to improve the on-off current ratio and radio-frequency performances as well as the suppression of ambipolar current. All results demonstrate that the proposed device not only suppresses ambipolar current but also improves radio-frequency performance compared with the conventional DMCG TFET, which makes the proposed device a better application prospect in the advanced integrated circuits.
