Microbar Expands Beyond Litho Chemicals
As semiconductor fabrication processes require more numerous and more complex chemicals, chemical handling evolves from simple plumbing to sophisticated, yield-critical technology. Handling chemicals for a cleaning bath is relatively easy, as the system only needs to maintain the manufacturer's supplied purity. Other chemicals have more complicated requirements. For example, slurries for chemical mechanical planarization (CMP) require careful control of pH and particle size. Dead volumes in the distribution system can allow formation of scratch-inducing agglomerates. In copper electroplating, the bath chemistry affects the deposition rate and film quality.
New chemicals also require new waste handling procedures. Copper-laden waste slurry is more toxic and difficult to neutralize than waste acid from a cleaning bath. Meanwhile, regulatory agencies are requiring more rigorous tracking and control of all fab chemicals.
Microbar (Sunnyvale, CA) recently announced plans to apply its experience with photoresist handling to these CMP, electroplating, liquid source CVD, and other new process areas. The company, founded in 1991, developed an automated chemical dispense system for lithography in collaboration with Intel. As president and CEO Bruce Juhola explained, bulk distribution and waste collection systems for photolithography chemicals evolved as the company gained expertise. Until now, the company's growth has been based on closed-loop chemical management for photolithography.
Bob MacKnight, recently appointed executive VP of business development, emphasized that photo chemical handling is not just a plumbing problem. The dispense system can increase process variability, or can help to control it. For instance, microbubbles trapped in the resist behave like particles, preventing correct exposure. Turbulent flow in the dispense system can promote formation of these bubbles, while other designs can encourage them to outgas. Similarly, shearing of the long chain polymers used in resist formulations degrades optical performance.
Deep ultraviolet (DUV) lithography presents additional complications, and Microbar has worked with chemical suppliers to address them. For instance, Juhola said, DUV resists tend to gel, and are very sensitive to oxygen exposure.
Microbar's photochemical management products have powered the company's 65% compound annual growth rate since 1991. Now, Juhola said, "We intend to continue this aggressive pace by expanding into other rapidly growing sectors of the semiconductor industry." As part of this effort, the company recently finalized the expansion of its manufacturing center, gaining a four-fold increase in manufacturing capacity.
For more information: Microbar, Inc. 1252 Orleans Drive Sunnyvale, CA 4089-1137. Tel: 408 541 1040, fax: 408 541 1441.
By Katherine Derbyshire