利用大面积硅片制作 X 射线光栅和硅基微通道板等都涉及硅的热氧化工艺。热氧化使具有高深宽比微结构的大面积硅片产生形变, 严重影响了这些器件的应用。本文以 5 英寸硅片为例, 研究了硅基微结构在热氧化过程中的变形问题, 定性分析了产生形变的力学因素, 提出了减小形变的氧化方法。首先实验制作了具有高深宽比微结构的硅片, 采用不同的氧化方法, 比较了变形的大小。结果表明, 通过控制热氧化过程中的温度来控制热膨胀系数和在热氧化过程中施加外部热塑应力等方法能够有效地减小热氧化变形量。

The fabrication of X-ray grating and silicon-based micro-channel plate on the large area silicon wafer involves the thermal oxidation of silicon which can greatly deform the wafer with microstructures of high-aspect-ratio, hindering the practical applications of the silicon-based devices. The thermal oxidation deformation of a 5-inch silicon wafer was experimentally studied and the mechanical factors affecting the deformation were analyzed. The method to decrease the deformation was also provided. The wafers with microstructures of high aspect-ratio were firstly fabricated by use of the photo-assisted electrochemical etching technique, and then different thermal oxidation methods were experimented, and lastly the deformation was compared. The results show that the deformation of large area silicon wafer can be decreased greatly by adjusting the thermal oxidation temperature to minimize the thermal expansion coefficient and by exerting an external force on silicon wafer during the thermal oxidation process.