Design Considerations
Designing for highest yields for today’s Advanced Technology nodes (45nm and below) requires specific process architectures and an understanding of the physics of semiconductor processing.  From the perspective of the architecture, we consider thermal transport mechanisms (conduction, convection and radiation) and how to minimize uncertainties, errors and variables. When we consider a patterned wafer from the perspective of the physics of processing, the wafer employs many materials which means variation of thermal effects from emissivity and thermal expansion. In addition, there are many different pattern periodicities (similar to diffraction gratings of different spacings) which couple to many frequencies in the visible spectrum. These facts give rise to what we observe as “the pattern effect”, thermal non-uniformity of processing, and are exacerbated when photons (lamps) are used as the main heating mechanism.


How WaferMasters Achieves Superior Yields and Performance
Superior on-Wafer REPEATABILITY is the Key to Yield Improvement. Once the process is qualified,

     REPEATABILITY = YIELD…

Compact Isothermal Process Module Design Is the KEY – The Process Module provides a very large, stable thermal mass which efficiently transfers heat to the wafer. The process module is maintained at a consistent temperature. The thermal characteristics of the module remain invariant. Thus on-wafer results are REPEATABLE wafer to wafer, week to week and month to month!

Excellent Uniformity – The Process Module presents a nearly Isothermal environment to the wafer which translates to excellent on-wafer uniformity.

Minimum Added Stress - The Isothermal process environment minimizes thermal stress by keeping the wafer in thermal equilibrium as much as possible.

Minimum Pattern Effect - No Lamps.  WaferMasters minimizes radiation transfer using conduction and convection as thermal transfer mechanisms. There is never any thermal overshoot!

Reliability by Design - MTBF > 5000hr (greater than 7 months!). WaferMasters’ design leaves nothing to chance. Moving parts, interlocks and unnecessary complexity are minimized.  

WaferMasters Leaves Nothing to Chance - Minimum Variables, Minimum Uncertainty = Maximum Repeatability     WaferMasters’ Un-Compromising Design Rules reduces uncertainty and errors in every detail.