Choi Ji-Ho, Lee Woo-Guk, Shim Tae-Hun, Park Jea-Gun
Department of Electronic Engineering, Hanyang University, Seoul 04763, Republic of Korea.
Department of Nanoscale Semiconductor Engineering, Hanyang University, Seoul 04763, Republic of Korea.
Nanomaterials (Basel). 2023 Jan 18;13(3):390. doi: 10.3390/nano13030390.
Fumed silica-based ultra-high-purity synthetic quartz powder was developed via the sol-gel process to apply to quartz wares and quartz crucibles for use in advanced semiconductor processes. The process conditions of preparing potassium silicate solution, gelation, and cleaning were optimized, i.e., the relative ratio of fumed silica (10 wt%) to KOH (4 wt%) for potassium silicate solution, gelation time 3 h, and cleaning for 1 h with 5 wt% HCl solution. It was observed that the gelation time strongly affected the size distribution of the quartz powder; i.e., a longer gelation time led to a larger size (d50) of the synthesized quartz powder: 157 μm for 2 h and 331 μm for 5 h. In particular, it was found that the morphology of the as-synthesized quartz powder greatly depended on the pulverizing process; i.e., the shape of quartz powder was shown to be rod-shaped for the without-gel-pulverizing process and granular-shaped with the process. We expect that the fumed silica-based ultra-high-purity quartz powder with an impurity level of 74.1 ppb synthesized via the sol-gel process is applicable as a raw material for quartz wares and crucibles for advanced semiconductor processes beyond the design rule of 3 nm.
通过溶胶 - 凝胶工艺开发了基于气相二氧化硅的超高纯合成石英粉，用于先进半导体工艺中的石英制品和石英坩埚。优化了制备硅酸钾溶液、凝胶化和清洗的工艺条件，即硅酸钾溶液中气相二氧化硅（10 wt%）与氢氧化钾（4 wt%）的相对比例、凝胶化时间3小时以及用5 wt%盐酸溶液清洗1小时。观察到凝胶化时间对石英粉的尺寸分布有很大影响；即较长的凝胶化时间导致合成石英粉的尺寸（d50）更大：2小时时为157μm，5小时时为331μm。特别地，发现合成石英粉的形态很大程度上取决于粉碎工艺；即无凝胶粉碎工艺下石英粉形状为棒状，有该工艺时为颗粒状。我们期望通过溶胶 - 凝胶工艺合成的杂质水平为74.1 ppb的基于气相二氧化硅的超高纯石英粉可作为先进半导体工艺中石英制品和坩埚的原料，用于3纳米以下的设计规则。
