Kent Tyler, Tang Kechao, Chobpattana Varistha, Negara Muhammad Adi, Edmonds Mary, Mitchell William, Sahu Bhagawan, Galatage Rohit, Droopad Ravi, McIntyre Paul, Kummel Andrew C
Materials Science and Engineering Department, University of California, San Diego, California 9500, USA.
Materials Science and Engineering Department, Stanford University, Stanford, California 94305, USA.
J Chem Phys. 2015 Oct 28;143(16):164711. doi: 10.1063/1.4934656.
Current logic devices rely on 3D architectures, such as the tri-gate field effect transistor (finFET), which utilize the (001) and (110) crystal faces simultaneously thus requiring passivation methods for the (110) face in order to ensure a pristine 3D surface prior to further processing. Scanning tunneling microscopy (STM), x-ray photoelectron spectroscopy (XPS), and correlated electrical measurement on MOSCAPs were utilized to compare the effects of a previously developed in situ pre-atomic layer deposition (ALD) surface clean on the InGaAs (001) and (110) surfaces. Ex situ wet cleans are very effective on the (001) surface but not the (110) surface. Capacitance voltage indicated the (001) surface with no buffered oxide etch had a higher C(max) hypothesized to be a result of poor nucleation of HfO2 on the native oxide. An in situ pre-ALD surface clean employing both atomic H and trimethylaluminum (TMA) pre-pulsing, developed by Chobpattana et al. and Carter et al. for the (001) surface, was demonstrated to be effective on the (110) surface for producing low D(it) high C(ox) MOSCAPs. Including TMA in the pre-ALD surface clean resulted in reduction of the magnitude of the interface state capacitance. The XPS studies show the role of atomic H pre-pulsing is to remove both carbon and oxygen while STM shows the role of TMA pre-pulsing is to eliminate H induced etching. Devices fabricated at 120 °C and 300 °C were compared.
当前的逻辑器件依赖于三维架构，例如三栅极场效应晶体管（鳍式场效应晶体管，finFET），它同时利用（001）和（110）晶面，因此需要对（110）面采用钝化方法，以便在进一步处理之前确保有一个纯净的三维表面。利用扫描隧道显微镜（STM）、X射线光电子能谱（XPS）以及对金属氧化物半导体电容（MOSCAP）进行的相关电学测量，来比较先前开发的原位预原子层沉积（ALD）表面清洁对铟镓砷（InGaAs）（001）和（110）表面的影响。异位湿法清洗在（001）表面非常有效，但在（110）表面则不然。电容电压表明，没有进行缓冲氧化物蚀刻的（001）表面具有较高的C（max），据推测这是由于HfO2在原生氧化物上成核不良所致。由Chobpattana等人和Carter等人开发的、用于（001）表面的同时采用原子氢和三甲基铝（TMA）预脉冲的原位预ALD表面清洁，被证明在（110）表面上对于制造低界面陷阱密度（Dit）、高氧化层电容（Cox）的MOSCAP是有效的。在预ALD表面清洁中加入TMA会导致界面态电容的幅度减小。XPS研究表明原子氢预脉冲的作用是去除碳和氧，而STM表明TMA预脉冲的作用是消除氢诱导的蚀刻。比较了在120°C和300°C下制造的器件。
