热载流子应力感应n-MOSFETsGIDL特性退化的机理

对不同栅氧化物ｎ－ＭＯＳＦＥＴｓ的ＧＩＤＬ（Ｇａｔｅ－ＩｎｄｕｃｅｄＤｒａｉｎＬｅａｋａｇｅ）特性在不同热载流子应力下的退化行为进行了研究．发现ＧＩＤＬ的漂移对栅电压十分敏感,在ＶＧ＝０．５ＶＤ的应力条件下呈现最大．通过对漏极附近二维电场及载流子分布的模拟,引入“亚界面陷阱”概念,对所涉及的机理提出了新见解,认为：在应力期间,亚界面和体氧化物空穴陷阱的解陷分别相应于ＶＧ＝０．５ＶＤ和ＶＧ＝ＶＤ两种典型应力下ＧＩＤＬ的漂移．实验还观察到Ｎ２Ｏ氮化,特别是Ｎ２Ｏ退火ＮＨ３氮化的ｎ－ＭＯＳＦＥＴｓ比常规热氧化ｎ     

多晶硅栅光刻前后注F对MOS器件辐射特性的影响

分析研究了Ｈ２＋Ｏ２合成栅氧化、多晶硅栅光刻前后注Ｆ和Ｐ的沟和Ｎ沟ＮＯＳＦＥＴ，在最劣γ辐照偏置下的阈电压和Ｉｄｓ－Ｖｇｓ亚阈特性的辐射影响应。结果表明，多晶硅栅光刻前注Ｆ比光刻后注Ｆ和未注Ｆ，具有更强的抑制辐射感生氧化物电荷积累和界面态生长的能力。其辐射敏感性的降低可能归结为ＳｉＯ２栅介质和Ｓｉ／ＳｉＯ２界面附近Ｆ的浓度相对较大以及栅场介质中Ｆ注入缺陷相对较少所致。     

多晶硅栅光刻前后注F对MOS器件辐照特性的影响

分析研究了Ｈ２＋Ｏ２合成栅氧化、多晶硅栅光刻前后注Ｆ和Ｐ的沟和Ｎ沟ＮＯＳＦＥＴ，在最劣γ辐照偏置下的阈电压和Ｉ（ｄｓ）－Ｖ（ｇｓ）亚阈特性的辐射影响应．结果表明，多晶硅栅光刻前注Ｆ比光刻后注Ｆ和未注Ｆ，具有更强的抑制辐射感生氧化物电荷积累和界面态生长的能力．其辐射敏感性的降低可能归结为ＳｉＯ２栅介质和Ｓｉ／ＳｉＯ２界面附近Ｆ的浓度相对较大以及栅场介质中Ｆ注入缺陷相对较少所致．     

工艺参数对真空紫外光直接光CVDSiO2—Si界面特性的影响

采用高频（１ＭＨｚ）Ｃ－Ｖ测试和红外谱，研究了工艺参数对ＸＣ激发真空紫外光直接光ＣＶＤＳｉＯ２的ＳｉＯ２／Ｓｉ界面特性的影响。结果表明，衬底温度Ｔｓ对固定氧化物电荷密度△Ｎｏｔ、慢界面态密度△Ｎ的影响比反应室总气压ＰＣ和ＳｉＨ４／Ｏ分压比显著。△Ｎｏｔ和△Ｎｓｔ在１１０℃附近有极小值。约为１０＾１０ｃｍ＾－１２量级。Ｔｓ〉１２０℃，△Ｎｏｔ呈正电荷性，Ｔｓ〈１１０℃，△Ｎｏｔ呈负电荷性，Ｓｉ－Ｏ－     

工艺参数对真空紫外光直接光CVD SiO2／Si界面特性的影响

采用高频（１ＭＨｚ）Ｃ－Ｖ测试和红外谱，研究了工艺参数对Ｘｅ激发真空紫外光（ＶＵＶ）直接光ＣＶＤ ＳｉＯ２的ＳｉＯ２／Ｓｉ界面特性的影响。结果表明：衬底温度Ｔｓ对固定氧化物电荷密度ΔＮｏｔ、慢界面态密度ΔＮｓｔ的影响比反应室总气压Ｐｃ和ＳｉＨ２／Ｏ２分压比显著。ΔＮｏｔ和ΔＮｓｔ在１１０℃附近有极小值，大小为１０＾１０ｃｍ＾－２量级。Ｔｓ〉１２０℃，ΔＮｏｔ呈正电荷性，Ｔｓ〈１１０℃，ΔＮｏｔ呈负     

注F栅介持抗电离辐射损伤机理

对含Ｆ ＭＯＳ结构的抗电离辐射特性和机理进行了系统研究。其结果表明：Ｆ减少工艺过程引入栅介持的Ｅ　’中心缺陷和补偿Ｓｉ／ＳｉＯ２悬挂键的作用,将导致实始氧化物电荷和界面态密度的下降;栅ＳｉＯ２中的Ｆ主要以Ｆ离子和Ｓｉ－Ｆ结键的方式存在;含Ｆ栅介质中部分Ｓｉ－Ｆ键替换Ｓｉ－Ｏ应力键而使Ｓｉ／ＳｉＯ２界面应力得到释放,以及用较高键能的Ｓｉ－Ｆ键替换Ｓｉ－Ｈ弱键的有益作用是栅介质辐射敏感降低的根本原因;     

氮化N沟MOS场效应管的界面陷阱特性

一种经过氮化处理背面吸杂的Ｎ沟ＭＯＳ场效应管，在较宽的温度和偏置范围下对其内烁噪声进行测量，将经过不等时间吸杂处理后的器件的噪声能谱进行比较发现，器件经过短时间背面吸杂，其闪烁噪声降低，相长时间吸杂则噪声趋势，探究噪声能量谱与温度的依赖关系表明，器件的低频噪声是由载流子对Ｓｉ－ＳｉＯ２界面陷阱的热激发造成的，而背面吸杂则导致Ｓｉ－ＳｉＯ２的应力衰竭，进而改变了截面陷阱的能量分布。     

SiO2,α—Si,Si3N4薄膜在表面钝化中的选择应用

本文基于对Ｓｉ３Ｎ４、ＳｉＯ２、α－Ｓｉ薄膜本身结构及其层间结构的分析，在半导体器件的表面钝化中做了选择应用。并将此用于生产实践，在Ｓｉ３Ｎ４－α－Ｓｉ－ＳｉＯ２结构中解决了由ＳｉＯ２／Ｓｉ界面的表面电荷及ＳｉＯ２中Ｎａ＋的漂移运动等引起的器件电学特性变差的问题。     

NH_3－氮化N_2O~－生长氧化物的MOS特性

ＮＨ＿３－氮化Ｎ＿２Ｏ￣－生长氧化物的ＭＯＳ特性＝ＭＯＳｃｈａｒａｃｔｅｒｉｓｔｉｃｓｏｆＮＨ＿３ｎｉｔｒｉｄｅｄＮ＿２Ｏ￣－ｇｒｏｗｎｏｘｉｄｅｓ［刊，英］／Ｙｏｏｎ，Ｇ，Ｗ．…／／ＩＥＥＥＥｌｅｃ－ｔｒｏｎＤｅｖｉｃｅＬｅｔｔｅｒｓ．１９９３，１...     

Fe~＋和H~＋注入引起的Si／SiO_2界面重构现象

针对Ｓｉ－ＳｉＯ２过渡区对于离子注入较为敏感的特点，用１．２ＭｅＶ，剂量１×１０１０ｃｍ－２的Ｆｅ＋和Ｈ＋先后注入ＳｉＯ２－Ｓｉ样品，并用ＸＰＳ技术重点分析了Ｓｉ－ＳｉＯ２界面附近硅的化学结构、组分的变化。结果表明，在界面附近，除了Ｓｉ４＋，Ｓｉ０价态，还存在明显的Ｓｉ２＋价态。这和注入Ｈ＋产生的高温退火以及Ｓｉ—Ｓｉ键或Ｓｉ—Ｈ键的形成有关。     

Study on Nitridation-Induced Residual Stress near Si/SiO2 Interface in n-MOSFETs

本文借助氩离子(Ar     

Oxide thickness dependence of nitridation effects on TDDB characteristics

Wet oxide thicknesses dependence of nitridation effects on electrical characteristics, charge trapping properties and TDDB (Time Dependent Dielectric Breakdown) characteristics have been investigated. It is found that the difference of conduction current between the wet and nitrided wet oxide increases with increasing oxide thickness both for negative and positive bias to the gate until constant current stress is applied. After the stress, with decreasing oxide thickness both in wet and nitrided wet oxide leakage current increases. Up to 60 Å no difference was observed between the wet and nitrided wet oxide but at 50 Å nitrided wet oxide has less increase of current comparing to the wet oxide for the same stress. In wet oxide with increasing stress current density initial hole trap decreases but electron trap increases whereas in nitrided wet oxide has less initial hole trap and also electron trap is less comparing to the wet oxide. Both in wet and nitrided wet oxide for negative bias stress, time to 50 % breakdown decreases with decreasing thickness but at 50 Å a turn-around effect was observed due to nitridation i.e., the 50 % breakdown time is greater for nitrided wet oxide comparing to the wet oxide. On the contrary, for positive bias stress 50 % breakdown time increases with decreasing oxide thickness both in wet and nitrided wet oxide. For positive bias also a turn-around effect is observed at 50 Å i.e., 50% breakdown time is less in nitrided wet oxide comparing to the wet oxide. The improved reliability of nitrided wet oxide at the thin region of 50 Å seems to be due to the increase of more Si---N bond to the interface of oxide and Si comparing to the thick oxide of above 60 Å for the same nitridation conditions.     

Comparison of neutral electron trap generation by hot-carrierstress in n-MOSFET's with oxide and oxynitride gate dielectrics

A comparative study of neutral electron-trap generation due to hot-carrier stress in n-MOSFETs with pure oxide, NH₃-nitrided oxide (RTN), and reoxidized nitrided oxide (RTN/RTO) as gate dielectrics is reported. Results show that neutral electron trap generation is considerably suppressed by nitridation and reoxidation. The nature of neutral traps is described based on the kinetics of trap filling by electron injection into the gate dielectrics immediately after channel hot-electron stress (CHES). Improved endurance of the RTN and RTN/RTO oxides is explained using physical models related to interfacial strain relaxation     

The effects of thermal nitridation conditions on the reliability of thin nitrided oxide films

MIS capacitors on n-type silicon substrate with thin oxide films thermally nitrided in NH3gas ambient at different temperatures and for different times have been fabricated. The effects of nitridation temperature and time on the properties of the thin nitrided oxide films have been examined and analyzed by using a constant current stress. It is found that the oxide films nitrided at 900°C exhibit much improved total charge to breakdown and interface trap generation if proper nitridation time is used. The superior characteristics of the fabricated nitrided oxide films using the proposed optimum conditions are suitable for existing CMOS/VLSI applications.     

Carrier trapping in thin N2O-grown oxynitride/oxide di-layer for PowerMOSFET devices

A detailed study of the carrier trapping properties shown by the silicon/oxynitride/oxide gate layers in PowerVDMOS technologies is reported. A quantitative analysis of hole and electron trap densities versus the specific N₂O based nitridation process, extracted from Fowler–Nordheim constant current stress kinetics, allows a deep understanding of the role played by those defects in the susceptibility of every nitrided layer.     

氮化H_2-O_2合成薄栅氧抗辐照特性

对氮化 H2 - O2 合成薄栅氧抗辐照性能进行了研究 ,将 H2 - O2 合成和氮氧化栅两种技术结合起来 ,充分利用两者的优点制成三层结构的 Sandwich栅 ,对比常规氧化、H2 - O2 合成氧化和氮化 H2 - O2 合成氧化三种方式及不同退火条件 ,得出氮化 H2 - O2 合成氧化方法抗辐照性能最佳 ,采用硅化物工艺加快速热退火是未来抗辐照工艺发展的趋势 ;并对氮化 H2 - O2 合成栅的抗辐照机理进行了研究     

Effect of nitridation on the reliability of thick gate oxides

In this work the effect of nitridation on the reliability of thick (60 nm) gate oxides used in discrete power MOSFETs is investigated. Nitridation was carried out by post-oxidation anneal in N₂O at 1000 °C. Secondary ion mass spectroscopy characterization did show that the nitrogen resulting from N₂O nitridation piles up in the oxide at the Si–SiO₂ interface regardless of nitridation time. The results obtained show improved breakdown field (E_bd), and charge-to-breakdown (Q_bd) characteristics for nitrided thick oxides. Also, lower mid-bandgap interface trap density (D_it) was observed in the case of nitrided oxides. Key conclusion from this experiment is that nitridation of thick (>50 nm) gate oxide performed to suppress boron penetration into the MOSFET channel region is not having an adverse effect on its electrical characteristics.     

Electrical properties of MOSFET's with N2O-nitridedLPCVD SiO2 gate dielectrics

Electrical properties of MOSFETs with gate dielectrics of low-pressure chemical-vapor-deposited (LPCVD) SiO₂ nitrided in N₂O ambient are compared to those with control thermal gate oxide. N₂O nitridation of CVD oxide, combines the advantages of interfacial oxynitride growth and the defectless nature of CVD oxide. As a result, devices with N₂O-nitrided CVD oxide show considerably enhanced performance (higher effective electron mobility), improved reliability (reduced charge trapping, interface state generation, and transconductance degradation), and better time-dependent dielectric breakdown (TDDB) properties (t_BD ) compared to devices with control thermal oxide     

多晶硅后热退火引起SiO_2栅介质可靠性下降的原因分析及其抑制方法

实验研究表明 ,多晶硅后的高温退火明显引起热 Si O2 栅介质击穿电荷降低和 FN应力下电子陷阱产生速率增加 .采用 N2 O氮化则可完全消除这些退化效应 ,而且氮化栅介质性能随着退火时间增加反而提高 .分析认为 ,高温退火促使多晶硅内 H扩散到 Si O2 内同 Si— O应力键反应形成 Si— H是多晶硅后 Si O2 栅介质可靠性退化的主要原因 ;氮化抑制退化效应是由于 N “缝合”了 Si O2 体内的 Si— O应力键缺陷 .     

Enhanced negative substrate bias degradation in nMOSFETs with ultrathin plasma nitrided oxide

The degradation induced by substrate hot electron (SHE) injection in 0.13-/spl mu/m nMOSFETs with ultrathin (/spl sim/2.0 nm) plasma nitrided gate dielectric was studied. Compared to the conventional thermal oxide, the ultrathin nitrided gate dielectric is found to be more vulnerable to SHE stress, resulting in enhanced threshold voltage (V/sub t/) shift and transconductance (G/sub m/) reduction. The severity of the enhanced degradation increases with increasing nitrogen content in gate dielectric with prolonged nitridation time. While the SHE-induced degradation is found to be strongly related to the injected electron energy for both conventional oxide , and plasma-nitrided oxide, dramatic degradation in threshold voltage shift for nitrided oxide is found to occur at a lower substrate bias magnitude (/spl sim/-1 V), compared to thermal oxide (/spl sim/-1.5 V). This enhanced degradation by negative substrate bias in nMOSFETs with plasma-nitrided gate dielectric is attributed to a higher concentration of paramagnetic electron trap precursors introduced during plasma nitridation.