PD SOI nMOSFETs中浮体效应对辐照性能的影响

在SIMOX衬底上制备了H形栅和环形栅PD SOI nMOSFETs,并研究了浮体效应对辐照性能的影响.在106rad(Si)总剂量辐照下,所有器件的亚阈特性未见明显变化.环形栅器件的背栅阈值电压漂移比H型栅器件小33%,其原因是碰撞电离使环形栅器件的体区电位升高,在埋氧化层中形成的电场减小了辐照产生的损伤.浮体效应有利于改进器件的背栅抗辐照能力.     

亚微米PD CMOS/SOI工艺及H栅单边体引出研究

研究开发了0.4 μm PD CMOS/SOI工艺,试制出采用H栅双边体引出的专用电路.对应用中如何克服PD SOI MOSFET器件的浮体效应进行了研究;探讨在抑制浮体效应的同时减少对芯片面积影响的途径,对H栅双边体引出改为单边体引出进行了实验研究.对沟道长度为0.4 μm、0.5 μm、0.6 μm、0.8 μm的H栅PD SOI MOSFET单边体引出器件进行工艺加工及测试,总结出在现有工艺下适合单边体引出方式的MOSFET器件尺寸,并对引起短沟道PMOSFET漏电的因素进行了分析,提出了改善方法;对提高PD CMOS/SOI集成电路的设计密度和改进制造工艺具有一定的指导意义.     

SOI器件中瞬态浮体效应的模拟与分析

针对SOI器件中的瞬态浮体效应进行了一系列的数值模拟,通过改变器件参数,比较系统地考察了SOI器件中瞬态浮体效应,同时也研究和分析了瞬态浮体效应对CMOS/SOI电路(以环振电路为例)的影响,并提出了抑制器件浮体效应的器件结构和参数优化设计.     

SOI器件中瞬态浮体效应的模拟与分析

针对 SOI器件中的瞬态浮体效应进行了一系列的数值模拟 ,通过改变器件参数 ,比较系统地考察了 SOI器件中瞬态浮体效应 ,同时也研究和分析了瞬态浮体效应对 CMOS/SOI电路 (以环振电路为例 )的影响 ,并提出了抑制器件浮体效应的器件结构和参数优化设计 .     

提高SOI器件和电路性能的研究

在分析SOI器件的浮体效应、击穿特性、背栅阈值、边缘漏电、ESD及抗辐照特性的基础上,提出了提高SOI器件和电路性能的技术途径.体接触是防止浮体效应的最好方法;正沟道和背沟道的BF2/B离子注入可以分别满足阈值和防止背栅开启的需要;SOI器件栅电极的选取严重影响器件的性能;源区的浅结有助于减小寄生npn双极晶体管的电流增益;而自对准硅化物技术为SOI器件优良特性的展现发挥了重要作用.研究发现,采用综合加固技术的nMOS器件,抗总剂量的水平可达1×106rad(Si).     

提高SOI器件和电路性能的研究

在分析SOI器件的浮体效应、击穿特性、背栅阈值、边缘漏电、ESD及抗辐照特性的基础上，提出了提高SOI器件和电路性能的技术途径. 体接触是防止浮体效应的最好方法；正沟道和背沟道的BF2/B离子注入可以分别满足阈值和防止背栅开启的需要；SOI器件栅电极的选取严重影响器件的性能； 源区的浅结有助于减小寄生npn双极晶体管的电流增益；而自对准硅化物技术为SOI器件优良特性的展现发挥了重要作用. 研究发现，采用综合加固技术的nMOS器件，抗总剂量的水平可达1E6rad(Si).     

提高SOI器件和电路性能的研究

在分析SOI器件的浮体效应、击穿特性、背栅阈值、边缘漏电、ESD及抗辐照特性的基础上,提出了提高SOI器件和电路性能的技术途径.体接触是防止浮体效应的最好方法;正沟道和背沟道的BF2/B离子注入可以分别满足阈值和防止背栅开启的需要;SOI器件栅电极的选取严重影响器件的性能;源区的浅结有助于减小寄生npn双极晶体管的电流增益;而自对准硅化物技术为SOI器件优良特性的展现发挥了重要作用.研究发现,采用综合加固技术的nMOS器件,抗总剂量的水平可达1×106rad(Si).     

一种抗总剂量辐照的新型PD SOI器件

提出了一种具有叠层埋氧层的新栅型绝缘体上硅(SOI)器件。针对SOI器件的抗总电离剂量(TID)加固方案,对绝缘埋氧层(BOX)采用了叠层埋氧方案,对浅沟槽隔离(STI)层采用了特殊S栅方案。利用Sentaurus TCAD软件,采用Insulator Fixed Charge模型设置固定电荷密度,基于0.18μm CMOS工艺对部分耗尽(PD)SOI NMOS进行了TID效应仿真,建立了条栅、H栅、S栅三种PD SOI NMOS器件的仿真模型。对比三种器件辐照前后的转移特性曲线、阈值电压漂移量、跨导退化量,验证了该器件的抗TID辐照性能。仿真结果表明,有S栅的器件可以抗kink效应,该PD SOI NMOS器件的抗TID辐照剂量能力可达5 kGy。     

部分耗尽型SOI CMOS模拟电路设计研究

介绍了部分耗尽型SOI MOS器件浮体状态下的Kink效应及对模拟电路的影响.阐述了4种常用体接触方式及其他消除部分耗尽型SOI MOS器件Kink效应的工艺方法,同时给出了部分耗尽型SOIMOSFET工作在浮体状态下时模拟电路的设计方法.     

一种新的部分耗尽SOI器件BTS结构

提出了一种新的部分耗尽SOI体接触技术,与其它体接触技术相比,该方法可以有效抑制SOI器件的浮体效应。形成多晶硅栅之前在源区进行大剂量P＋杂质注入,然后形成非对称源区浅结结构。然后生长硅化物电极,厚的硅化物穿透源区浅结与下面高浓度的体区形成欧姆接触。二维器件模拟表明该结构可以有效降低强反型区体区电势,从而抑制了浮体效应。     

Comprehensive study on low-frequency noise characteristics insurface channel SOI CMOSFETs and device design optimization for RF ICs

Low-frequency (LF) noise, a key figure-of-merit to evaluate device technology for RF systems on a chip, is a significant obstacle for CMOS technology, especially for partially depleted (PD) silicon-on-insulator (SOI) CMOS due to the well-known kink-induced noise overshoot. While the dc kink effect can be suppressed by either using body contact technologies or shifting toward fully depleted (FD) operation, the noise overshoot phenomena still resides at high frequency for either FD SOI or poor body-tied (BT) SOI CMOSFETs. In this paper, floating body-induced excess noise in SOI CMOS technology is addressed, including the impact from floating body effect, pre-dc kink operation, and gate overdrive, followed by the proposal of a universal LF excess noise model. As the physical mechanism behind excess noise is identified, this paper concludes with the suggestion of a device design methodology to optimize LF noise in SOI CMOSFET technology     

AC floating body effects and the resultant analog circuit issues insubmicron floating body and body-grounded SOI MOSFET's

We report the extensive study on ac floating body effects of different SOI MOSFET technologies. Besides the severe kink and resultant noise overshoot and degraded-distortion in partially depleted (PD) floating body SOI MOSFET's, we have investigated the residue ac floating body effects in fully depleted (FD) floating body SOI MOSFET's, and the different body contacts on PD SOI technologies. It is important to note that there is a universal correlation between ac kink effect and Lorentzian-like noise overshoot regardless of whether the body is floating or grounded. In addition, it was found that third-order harmonic distortion is very sensitive to floating body induced kink or deviation on output conductance due to the finite voltage drop of body resistance. These results provide device design guidelines for SOI MOSFET technologies to achieve comparable low-frequency noise and linearity with Bulk MOSFET's     

Direct tunneling-induced floating-body effect in 90-nm pseudo-kink-free PD SOI pMOSFETs with DTMOS-like behavior and low input power consumption

This paper reports the investigation of the direct tunneling-induced floating-body effect in 90-nm H-gate floating body partially depleted (PD) silicon-on-insulator (SOI) pMOSFETs with dynamic-threshold MOS (DTMOS)-like behavior and low input power consumption. Based on this paper, with the decrease of the gate-oxide thickness, the direct-tunneling current will dominate the floating body potential of H-gate PD SOI pMOSFETs, which makes the floating body potential highly gate voltage dependent like DTMOS behavior with a larger drain current. However, the input power consumption is still kept lower. Simultaneously, the highly gate voltage dependent direct-tunneling current will reduce the influence of the impact ionization current on the neutral region with a higher kink onset-voltage. It contributes to the pseudo-kink-free phenomenon in 90-nm H-gate floating body PD SOI pMOSFETs.     

Phase noise characteristics associated with low-frequency noise insubmicron SOI MOSFET feedback oscillator for RF IC's

Phase noise in silicon-on-insulator (SOI) MOSFET feedback oscillators for RF IC applications is investigated. The observed correlation between the oscillator's high frequency phase noise and the transistor's low-frequency noise characteristics demonstrates that the phase noise overshoot still exists in partially-depleted (PD) floating body SOI nMOS Colpitts oscillators. These results suggest that kink-induced effects associated with low-frequency components of the signal are upconverted into the ideally kink-free high frequency domain operation mode of PD floating body SOI oscillators     

Gate tunneling leakage current behavior of 40 nm PD SOI NMOS device considering the floating body effect

This paper reports an analysis of floating body effect related gate tunneling leakage current behavior of the 40 nm PD SOI NMOS device using bipolar/MOS equivalent circuit approach. As confirmed by the experimentally measured data, the bipolar/MOS equivalent circuit approach could predict the gate tunneling leakage current behavior, which is strongly affected by the parasitic bipolar device in the floating body as observed from the perpendicular electric field along the path of the U-shaped edges of the polysilicon gate.     

Gate-induced floating body effect excess noise in partially depleted SOI MOSFETs

Low frequency excess noise associated to gate-induced floating body effect is for the first time reported in Partially Depleted SOI MOSFETs with ultrathin gate oxide. This was investigated with respect to floating body devices biased in linear regime. Due to a body charging from the gate, a Lorentzian-like noise component superimposes to the conventional 1/f noise spectrum. This excess noise exhibits the same behavior as the Kink-related excess noise previously observed in Partially Depleted devices in saturation regime.     

Influence of Floating Body Effect on Radiation Hardness of PD SOI nMOSFETs

H-gate and closed-gate PD SOI nMOSFETs are fabricated on SIMOX substrate,and the influence of floating body effect on the radiation hardness is studied.All the subthreshold characteristics of the devices do not change much after radiation of the total dose of 1e6rad(Si).The back gate threshold voltage shift of closed-gate is about 33% less than that of Hgate device.The reason should be that the body potential of the closed-gate device is raised due to impact ionization,and an electric field is produced across the BOX.The floating body effect can improve the radiation hardness of the back gate transistor.     

部分耗尽SOI MOSFETs中沟道的非对称掺杂效应

利用二维模拟软件对部分耗尽SoI器件中的非对称掺杂沟道效应进行了模拟.详细地研究了该结构器件的电学性能,如输出特性,击穿特性.通过本文模拟发现部分耗尽SOI非对称掺杂沟道相比传统的部分耗尽SOI,能抑制浮体效应,改善器件的击穿特性.同时跟已有的全耗尽SOI非对称掺杂器件相比,部分耗尽器件性能随参数变化,在工业应用上具有可预见性和可操作性.因为全耗尽器件具有非常薄的硅膜,而这将引起如前栅极跟背栅极的耦合效应和热电子退化等寄生效应.     

部分耗尽SOI MOSFETs中沟道的非对称掺杂效应

利用二维模拟软件对部分耗尽SoI器件中的非对称掺杂沟道效应进行了模拟.详细地研究了该结构器件的电学性能,如输出特性,击穿特性.通过本文模拟发现部分耗尽SOI非对称掺杂沟道相比传统的部分耗尽SOI,能抑制浮体效应,改善器件的击穿特性.同时跟已有的全耗尽SOI非对称掺杂器件相比,部分耗尽器件性能随参数变化,在工业应用上具有可预见性和可操作性.因为全耗尽器件具有非常薄的硅膜,而这将引起如前栅极跟背栅极的耦合效应和热电子退化等寄生效应.