Ultra-low on-resistance high voltage (> 600 V) SOI MOSFET with a reduced cell pitch
Ultra-low on-resistance high voltage (> 600 V) SOI MOSFET with a reduced cell pitch
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DOI：
10.1088/1674-1056/20/2/028501
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发表时间：
2011-02
影响因子：
1.7
通讯作者：
L. Xiaorong;Yao Guoliang;Chen Xi;Wang Qi;Ge Rui;F. Udrea
中科院分区：
文献类型：
--
作者：
L. Xiaorong;Yao Guoliang;Chen Xi;Wang Qi;Ge Rui;F. Udrea
提出了一种减小单元间距的低比导通电阻(RS，ON)绝缘体上硅沟槽MOSFET(metal—oxide—semiconductor—field—effect—transistor)。横向MOSFET具有多个沟槽：漂移区中的两个氧化物沟槽和延伸到掩埋氧化物(BOX)的沟槽栅极(SOI MT MOSFET)。首先，由于氧化物的介电常数低于硅的介电常数，氧化物沟槽提高了沿x方向的平均电场强度；其次，氧化物沟槽引起了多方向的耗尽，改善了SOI层的电场分布，增强了SOI层的约化表面场效应。它们都会导致较高的击穿电压(BV)。第三，氧化物沟槽导致漂移区在垂直方向上折叠，导致单元间距缩短和RS，ON减小。第四，延伸到箱体的沟槽栅极由于电子累积层而进一步降低了RS、ON。在相同的半单元间距21.5μm时，MTMOSFET的BV从传统SOI横向双扩散金属氧化物半导体的309V增加到632V，RS，ON从419mΩcm~2减少到36.6mΩcm~2。所提出的结构还有助于在相同击穿电压的情况下显著减小单元间距。
A low specific on-resistance (RS,on) silicon-on-insulator (SOI) trench MOSFET (metal—oxide—semiconductor—field—effect—transistor) with a reduced cell pitch is proposed. The lateral MOSFET features multiple trenches: two oxide trenches in the drift region and a trench gate extended to the buried oxide (BOX) (SOI MT MOSFET). Firstly, the oxide trenches increase the average electric field strength along the x direction due to lower permittivity of oxide compared with that of Si; secondly, the oxide trenches cause multiple-directional depletion, which improves the electric field distribution and enhances the reduced surface field (RESURF) effect in the SOI layer. Both of them result in a high breakdown voltage (BV). Thirdly, the oxide trenches cause the drift region to be folded in the vertical direction, leading to a shortened cell pitch and a reduced RS,on. Fourthly, the trench gate extended to the BOX further reduces RS,on, owing to the electron accumulation layer. The BV of the MT MOSFET increases from 309 V for a conventional SOI lateral double diffused metal—oxide semiconductor (LDMOS) to 632 V at the same half cell pitch of 21.5 μm, and RS,on decreases from 419 mΩcm2 to 36.6 mΩcm2. The proposed structure can also help to dramatically reduce the cell pitch at the same breakdown voltage.