The Applied Centura Transforma Etch with closed loop control is a breakthrough etch patterning system, delivering less than 5nm (3σ) lot-to-lot variation in final gate CD. Integrating optical metrology, onboard post-etch treatment, and closed loop data feedback, Transforma makes control of final gate critical dimension (CD) a reality in logic, SRAM, and DRAM integrated circuits for 90nm and the next several device generations.

The industry-proven DPS II etcher forms the core of the system, operating with the stability required for precise processing at sub-100nm nodes. Onboard optical CD (OCD) metrology and associated software analyze multi-dimensional feature measurements faster and more accurately than conventional metrology systems. High-volume, high-speed data streaming feeds these data forward to a multi-input/multi-output (MIMO) process control algorithm capable of accounting for first-, second-, and third-order contributors to pre-etch lithography variations. The etcher response then tailors processing for each incoming wafer by adjusting one or more recipe parameters. By thus eliminating the lot-to-lot signature typical of uni-parameter photoresist trim control, Transforma delivers the superior output consistency indispensable for ensuring greater yields of more valuable, higher speed devices.

Post-etch stabilization in an Axiom chamber ensures accurate post-etch/pre-clean OCD measurements without the wafers leaving the system. (In contrast, e-beam metrology cannot penetrate the stabilized etch byproducts to measure the true post-etch gate CD.) Post-etch data feed back to the process controller to validate and fine-tune the MIMO algorithm for run-to-run control. Full-spectrum, interferometric EyeD endpoint adds metrology accuracy equal to that of standalone tools for etch depth control on ultra-thin gate oxides and new gate dielectrics.

Transforma's integrated capabilities yield enhanced efficiency by shortening cycle time, reducing scrap, and increasing system availability. MIMO algorithm flexibility offers the advantage of accommodating device diversity in the production line, while the well-characterized, tunable trim function extends current lithography.