Fumed Silica-Based Ultra-High-Purity Synthetic Quartz Powder via Sol-Gel Process for Advanced Semiconductor Process beyond Design Rule of 3 nm

• Published in: Nanomaterials (Basel, Switzerland) Vol. 13; no. 3; p. 390
• Main Authors: Choi, Ji-Ho, Lee, Woo-Guk, Shim, Tae-Hun, Park, Jea-Gun
• Format: Journal Article
• Language: English
• Published: Switzerland MDPI AG 18.01.2023; MDPI
• Subjects: Analysis; Carbon; Chemical processes; Chemical reactions; Chemical synthesis; Cleaning; Crucibles; Gelation; Grinding (comminution); Heat resistance; High temperature; Identification and classification; Methods; Morphology; Potassium; Potassium silicates; Powder; Powders; Properties; Purity; Quartz; Raw materials; Silica; Silica fume; Silicones; Size distribution; Sol-gel processes; sol–gel process; Spectrum analysis; Synthesis; synthetic quartz powder; ultra-high purity; South Korea; United States > US; synthetic quartz powder; ultra-high purity; sol–gel process
• ISSN: 2079-4991; 2079-4991
• 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.