A single-trap study of PBTI in SiON nMOS transistors: Similarities and differences to the NBTI/pMOS case
A single-trap study of PBTI in SiON nMOS transistors: Similarities and differences to the NBTI/pMOS case
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SiON nMOS 晶体管中 PBTI 的单陷阱研究：与 NBTI/pMOS 情况的异同
DOI：
10.1109/irps.2014.6861195
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发表时间：
2014
期刊：
影响因子：
--
通讯作者：
T. Grasser
中科院分区：
文献类型：
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作者：
M. Waltl;W. Goes;K. Rott;H. Reisinger;T. Grasser
为了确定偏置温度不稳定性（BTI）可恢复成分背后的物理机制，近年来时间相关缺陷光谱（TDDS）被提出并得到广泛应用。TDDS利用了在纳米级器件中恢复是以离散步骤进行这一事实。通过分析这些步骤的统计特性，可以获得有关BTI退化机制的有价值信息。到目前为止，大多数单缺陷研究都集中在SiON器件的负偏置温度不稳定性（NBTI）以及高k栅极堆叠的正偏置温度不稳定性（PBTI）上。为了加深我们对导致这种有害现象的陷阱的理解，我们在此聚焦于SiON n型金属 - 氧化物 - 半导体场效应晶体管（nMOSFETs）中的PBTI，到目前为止对此还没有进行非常详细的研究。从大面积器件可知，PBTI/nMOS比NBTI/pMOS大约低一个数量级。与正偏置温度不稳定性由空穴俘获导致的pMOSFET不同，在nMOSFET的情况下必须考虑电子陷阱。我们在此表明，在nMOSFET中导致PBTI的缺陷具有与先前NBTI/pMOS研究中观察到的空穴陷阱类似的单个俘获行为以及对偏置和温度的依赖性。有趣的是，与pMOSFET一样，我们观察到开关和固定电荷陷阱，这使我们能够将先前提出的空穴俘获模型应用于nMOSFET中的电子俘获。
To identify the physical mechanism behind the recoverable component of the bias temperature instability (BTI), the time dependent defect spectroscopy (TDDS) has been recently proposed and used extensively. The TDDS makes use of the fact that in nano-scale devices the recovery proceeds in discrete steps. By analyzing the statistical properties of the steps, valuable information about the BTI degradation mechanisms can be obtained. So far, most single-defect studies have focused on NBTI in SiON devices as well as PBTI in high-k gate stacks. In order to deepen our understanding of the traps responsible for this detrimental phenomenon, we focus here on PBTI in SiON nMOSFETs, which have not been studied in great detail so far. From large-area devices it is known that PBTI/nMOS is about one order of magnitude lower than NBTI/pMOS. Unlike pMOSFETs, where hole trapping is responsible for BTI, in the case of nMOSFETs electron traps have to be considered.We show here that defects causing PBTI in nMOSFETs have a similar individual trapping behavior and dependence on the bias and temperature as observed for hole traps in previous NBTI/pMOS studies. Interestingly, like in pMOSFETs, we observe switching and fixed charge traps, which allows us to adapt our previously suggested model for hole capture to electron capture in nMOSFETs.