Online information source for semiconductor professionals

Product Briefing Outline: Advanced Metrology Systems (AMS) has launched the IR 3100S small spot MBIR (Model Based Infra-red Reflectometer) system. The IR 3100S is a highly automated, online measurement system that uses proprietary mid-IR optics. The 70 by 70 micron spot size targets 3D etched structures such as DRAM straight and bottle-shaped trenches, recess measurements along with stacked DRAM contact capacitor profiling and composition measurements.

Problem: As process nodes advance, device sizes shrink; a need was identified to measure smaller areas than the current IR system was capable of performing. The spot size of IR systems ranged from a few mm2 to a 200 by 800 micron spot of the current IR 3000/3100. Typically, this was insufficient to allow product wafer measurements within the scribe lines for composition measurements such as BPSG along with limiting the density of in-die uniformity measurements. Solutions to this problem in the past significantly affected the signal to noise of the measurement leading to poor repeatability and much longer data acquisition times.

Solution: The IR 3100S uses a new proprietary optical measurement system which results in a spot size (or minimum measured area) of 70 by 70 microns without sacrificing signal to noise or data acquisition time. When combined with the pattern recognition capability of Cognex ‘PATMAX' and real time auto-focus capability, the 3100S has the ability to do online measurements of product wafers in the scribe line or in the actual device.

Applications: This spot size enables more detailed uniformity measurements within devices of 3D etched structures such as DRAM straight and bottle-shaped trenches, recess measurements along with stacked DRAM contact capacitor profiling and composition measurements.

Platform: The IR 3100S uses the same AMS series 3000 platform, which is highly automated, incorporating the E84 capable dual loadport system. It can also be configured for 200/300mm or 150/200mm mixed wafer size operation as well as standard dual 300mm FOUP, 200mm SMIF or open cassette systems. As with all AMS systems, loadports can be changed in the field to allow reconfiguration of the wafer handling systems as customers change wafer sizes or automation needs. The automation backbone software is based on Peer Group's new advanced PTO3 automation solution and has been tested in fabs worldwide.

Availability: A demonstration system is available at AMS in Natick MA now. The first IR 3100S systems will ship in Q4 of 2007.