氢离子注入硅片退火行为的高压电镜原位观察

IN SITU OBSERVATION OF ANNEALING BEHAVIOR OF HYDROGEN IMPLANTED SILICON IN HIGH VOLTAGE ELECTRON MICROSCOPE

采用高压电子显微镜（ＨＶＥＭ）的原位观察技术，在１ＭＶ加速电压和室温至６５０℃加热条件下，观察了氢离子注入硅片中缺陷层的变化。在５００℃以下，氢离子注入缺陷层基本没有变化，在６５０℃保温时，缺陷的密度逐渐降低，样品中薄区域部分的缺陷在保温２０ｍｉｎ后消失，而厚区域部分在保温４０ｍｉｎ后仍存有部分缺陷，说明缺陷的变化与样品厚度有关。用氢的扩散理论讨论了这一现象。

In situ observation of microstructural defects in hydrogen implanted silicon annealed from room temperature to 650 ℃ has been carried out in a high voltage electron microscope operating at 1 MV. When the temeprature is below 500 ℃, no obvious change takes place in the defect layer caused by H + ion implantation. The density of defect decreases gradually when the temperature rises to 650 ℃. Defects in thin region of the sample disappear after annealing at 650 ℃ for 20 min, while some defects still exist in thick region of the sample after annealing for 40 min. This indicates that the evolution of defects depends on the thickness of the sample, which can be interpreted by the diffusion of hydrogen. It is proposed that diffusion occurs possibly through a hydrogen molecule form.