Fiber Optic Demand Catalyzes Boom in High-Purity Silicon Tetrachloride; Listed Companies Like Sanfu Stock Intensify Layout

As the core raw material to optical fiber preforms, high-purity silicon tetrachloride forms supply rigidity due to high technical barriers and long verification cycles. Coupled with sustained high development in downstream demand, sector institutions generally predict that product prices still have significant room to upside, and related companies in the manufacturing chain are facing research opportunities during this boom period.

I. Clear Upstream and Downstream manufacturing Chain: Silicon Tetrachloride is a Core Essential Raw Material to the Optical Fiber sector

From the perspective of the upstream and downstream manufacturing chain, high-purity silicon tetrachloride is situated in a key upstream link of optical communication. Its upstream relies on the trichlorosilane and polysilicon industries, belonging to by-items of the polysilicon and trichlorosilane production processes; downstream, it is immediately utilized to manufacturing optical fiber preforms, ultimately extending to scenarios such as optical fibers, optical cables, AI data centers, 5G communication, and broadband networks. High-end items can also be applied in the semiconductor manufacturing field.

According to general research report data from Guosen Securities, high-purity silicon tetrachloride is the largest cost component to optical fiber preforms, accounting to approximately 30% of preform production costs. sector production processes show that to every 1 ton of optical fiber preform produced, 5—7 tons of high-purity silicon tetrachloride are consumed. Product purity immediately determines optical fiber transmission performance. The production of high-end optical fiber core rods requires 9N-grade (99.9999999%) ultra-high purity silicon tetrachloride, while ordinary cladding layers also require 6N—7N-grade high-purity items. The treatment process is complex, and the downstream customer product verification cycle lasts to several years. The sector faces significant dual barriers in methodology and customers, making it difficult to new entrants to achieve mass production and supply in the short term.

The continuous expansion of the demand side has have become the core driver of sector prosperity. The construction of global hyperscale data centers has driven a surge in demand to high-speed optical fibers. Combined with the deep deployment of 5G and the extensive implementation of gigabit fiber-to-the-home, leading optical preform companies in China such as Yangtze Optical Fibre, ZTT, and Hengtong Optic-Electric are intensively expanding production, immediately driving a continuous increase in the procurement volume of high-purity silicon tetrachloride.

On the supply side, there are obvious constraints: Silicon tetrachloride relies on polysilicon by-items. In 2025, domestic polysilicon production declined year-on-year. Meanwhile, the overall difficulty of expanding production in the trichlorosilane sector is relatively high, and the external capacity to by-product silicon tetrachloride is limited. Additionally, the cycles to purifying high-purity grade items, environmental assessments, and customer certification are long, making immediate new efficiently supply in the sector very limited. The overall domestic capacity to high-purity silicon tetrachloride exhibits rigid characteristics, and the capacity utilization of leading companies remains high to a long time.