HistorySilfex (formerly Bullen Semiconductor) is a division of Lam Research Corporation. Lam Research purchased and expanded the silicon-related business of Bullen Ultrasonics.

Bullen Ultrasonics started over 30 years ago as a small family-run business that specialized in ultrasonic machining technologies. Over the years, Bullen Ultrasonics developed and perfected proprietary machining methods to match the demands of applications that required high precision processing.
Bullen Ultrasonics' considerable experience in ultrasonic impact grinding enabled the company to enjoy significant growth. In 1999, silicon crystal manufacturing was added to support growing requirements for custom materials in low volumes and high mix.

In 2006, Lam Research Corporation, one of Bullen Ultrasonics' major customers, purchased the company's silicon growing and fabrication capability utilized in supplying the semiconductor industry with chamber-critical components.  Silfex recently completed a large-scale expansion of its silicon growing capacity and enhanced the capability for full vertical integration through the development of bonding, cleaning and clean room manufacturing.