Role of oxygen impurities in etching of silicon by atomic hydrogena)
Role of oxygen impurities in etching of silicon by atomic hydrogena)
复制标题
氧杂质在原子氢蚀刻硅中的作用）
DOI：
10.1116/1.2884731
复制
发表时间：
2008
期刊：
影响因子：
--
通讯作者：
M. Vepřek
中科院分区：
文献类型：
--
作者：
S. Vepřek;Chunlin Wang;M. Vepřek
在纯氢辉光放电等离子体中，硅的蚀刻速率随着温度的升高而增加，在60-80 °C下达到约≥1100 A/s，并且在温度进一步升高时，蚀刻速率强烈降低，显示出Arrhenius样依赖性，负表观活化能为−1.5 kcal/mol。 当硅样品处于浮电位时，≥ 10at. ppm强烈降低蚀刻速率。当氧含量超过70 ppm时，蚀刻停止。在硅样品上施加负电位，然后用氢原子对硅进行化学腐蚀，可以通过离子轰击除去硅表面吸附的氧。在无氧体系中，氢原子的腐蚀是各向同性的。一个可控的几ppm的氧与负偏置的Si样品的组合的结果在高度各向异性蚀刻薄氧化物作为侧壁钝化。
In a pure-hydrogen glow discharge plasma, the etch rate of silicon increases with increasing temperature up to about ≥1100 A/s at 60–80 °C and, upon a further increase of the temperature, etch rate strongly decreases, showing Arrhenius-like dependence with negative apparent activation energy of −1.5 kcal/mol. When the Si sample is at the floating potential, oxygen impurities of ≥10 at. ppm strongly decrease the etch rate. At more than 70 ppm of oxygen, the etching stops. Oxygen adsorbed on the Si surface can be removed by ion bombardment when negative potential is applied to the Si sample and the Si is then etched chemically by H atoms. The etching by atomic hydrogen is isotropic in an oxygen-free system. A controllable addition of a few ppm of oxygen in combination with negative bias of the Si sample results in highly anisotropic etching with thin oxide acting as side-wall passivation.