OXIDE-GROWTH ON ETCHED SILICON IN AIR AT ROOM-TEMPERATURE
OXIDE-GROWTH ON ETCHED SILICON IN AIR AT ROOM-TEMPERATURE
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DOI：
10.1149/1.2134225
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发表时间：
1975-01-01
影响因子：
3.9
通讯作者：
PALMER, MJ
中科院分区：
文献类型：
--
作者：
RAIDER, SI;FLITSCH, R;PALMER, MJ
研究了室温下蚀刻硅晶片上氧化物的生长与蚀刻程序、晶片取向、掺杂剂浓度和紫外光暴露的关系。在用氢氟酸蚀刻后，在硅表面上快速沉积杂质膜。通过X射线光电子能谱（E 'SCA）将杂质吸附与氧化物生长区分开来。当与在解理硅表面上生长的氧化物相比时，杂质膜大大降低了初始氧化物生长速率。用ESCA和椭圆偏振法测定并比较了腐蚀表面上形成的氧化膜的厚度。描述了原子级清洁硅表面上硅与氧的相互作用（1）。用于这些研究的硅表面通常在超高真空中在升高的温度下制备。在半导体加工中具有实际重要性的相关问题是在室温下在蚀刻的硅单晶衬底上生长氧化膜（2-4）。膜生长的椭圆体，tric测量已被用于描述在初始膜快速形成后硅上的氧化物生长动力学（2，4）。超薄膜厚度的变化，确定从椭圆偏振数据，采用二氧化硅的折射率和处理的氧化物膜。虽然Archer（2）指出，在暴露于空气中24小时后，除了氧化膜外，还存在一层杂质层，可以用有机溶剂除去，但这些膜没有进行表征。最近对蚀刻硅表面的俄歇研究也表明，碳和氧都存在（5-8）。本工作描述了在室温下，用HF腐蚀法制备的硅表面上覆盖有吸附物时，氧化物的生长速率。X射线光电子能谱，或ESCA（化学分析电子能谱），在这里使用，以补充椭圆偏振测量蚀刻硅表面上的薄膜形成。ESCA特别适合作为检查~ 100埃厚的氧化膜的技术，并且可以提供光发射电子线强度和结合能方面的分析和键合数据。ESCA技术的基础是通过X射线激发原子的电子结构并分析光发射电子的动能。在1 keV能量范围内，单能非弹性散射光电子的平均自由程<30 A。对光电子线强度的贡献随离膜表面的距离呈指数下降。从核心能级激发的光电子主要是原子性质的，但会受到原子化学环境引起的结合能的变化。通过比较ESCA和椭偏测量的数据，对室温下腐蚀硅上形成的氧化膜进行了表征，确定了影响氧化膜生长的因素。
Oxide growth on etched silicon wafers at room temperature was studied as a function of etching procedure, wafer orientation, dopant concentration, and exposure to ultraviolet light. An impurity film was rapidly deposited on the silicon surface after etching with hydrofluoric acid. Impurity adsorption was distinguished from oxide growth by x-ray photoelectron spectroscopy (E'SCA). The impurity film greatly reduced the initial oxide growth rate when compared with oxide, growth on a cleaved silicon surface. The thickness of oxide films formed on etched surfaces was determined and compared using ESCA and ellipsometry.The interaction of silicon with oxygen on atomically clean silicon surfaces has been described (1). The silicon surface for these studies is generally prepared in ultra-high vacuum at elevated temperatures. A related problem of practical importance in semiconductor processing is the growth of oxide films at room temperature on etched silicon single-crystal substrates (2-4). Ellipsome, tric measurements of film growth have been used to describe oxide growth kinetics on silicon after an initial film is rapidly formed (2, 4). Changes in ultra-thin film thickness were determined from ellipsometric data by employing the index of refraction of silicon dioxide and treating the films as oxides. These films were not characterized although Archer (2) noted that an impurity layer, which could be removed with organic solvents, was present in addition to an oxide film after exposure to air for 24 hr. Recent Auger studies of etched silicon surfaces also indicated the presence of both carbon and oxygen (5-8). The present work describes the growth rate of an oxide at room temperature for a silicon surface prepared by e~ ching in HF and covered with adsorbates. X-ray photoelectron spectroscopy, or ESCA (electron spectroscopy for chemical analysis), is used here to complement ellipsometric measurements of ultrathin film formation on etched silicon surfaces. ESCA is particularly well suited as a technique for examination of oxide films~ 100A thick and can provide analytical and bonding data in terms of photoemitted electron line intensities and binding energies. The basis of the ESCA technique is the excitation of the electronic structure of an atom by x-rays and the analysis of the kinetic energies of the photoemitted electrons. The mean free paths of the monoenergetic, inelastically scattered photoelectrons are< 30A in the 1 keV energy range. Contributions to a photoelectron line intensity decrease exponentially with distance from the film surface. Photoelectrons excited from core levels are mainly atomic in character but are subject to shifts in binding energy caused by the chemical environment of the atoms. By comparing ESCA and ellipsometric data, the films formed on etched silicon at room temperature are characterized and those factors which affect oxide growth are determined.