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Tevet Integrated Metrology Emerges as Enabling in Shift to High Throughput Processing
TEVET INTEGRATED METROLOGY EMERGES AS ENABLING IN SHIFT TO HIGH THROUGHPUT PROCESSING
2X productivity change in semiconductor equipment CVD segment redefines metrology drivers
Yoknea’m, Israel, July 2, 2007
—Tevet Process Control Technologies today announced that recent and fundamental changes in the semiconductor Chemical Vapor Deposition (CVD) market segment have abruptly created the demand for high speed, every-wafer integrated metrology. Tevet’s unique patent pending parallel sensor Integrated Metrology Module (IMM) with its best-in-class two second per wafer measurement cycle is the only production proven IMM that can measure every wafer in the fastest CVD processes.
Excursions: Immediate Time-to-Detection Needed to Control Scrap in High Throughput CVD
A new generation of CVD and Plasma Enhanced CVD (PECVD) has been introduced that run at 2X the throughput of conventional cluster tools. “Throughputs of 150 wph and more can now be achieved in standard production for thin film deposition,” said Risto Puhakka, President of VLSI Research, Inc. “These throughputs can be sustained for critical films such as the increasingly implemented Anti-Reflective Coating (ARC) layers. With ARC layers, it is critical to control the film thickness to be able to successfully image photoresist in the subsequent lithography step. A small change in film thickness either locally (uniformity) or globally (across wafer) can result in lithography pattern aberrations that ultimately reduce end of line yield. The high speed of these new generation tools mean that stand-alone metrology tool sampling plans with over an hour between process and measurement would delay detection times to over 150 wafers. This could result in yield losses running into the hundreds of thousands of dollars per excursion before the conventional metrology sampling scheme would detect the processing error.” Fast time-to-detection for process excursions is paramount for high throughput process tools to eliminate exposure to unacceptable levels of scrap and rework.
Process: Every-Wafer Measurement Needed for Uptime & Control in High Throughput CVD
As noted in the International Technology Roadmap for Semiconductors Factory Integration section, chamber matching, reliability, processing speed, and single-wafer level tracking and control are among the “factors that impact productivity.” The new generation of CVD and PECVD tools’ high throughput is largely enabled by processing wafers in multiple chambers in parallel. However, with more wafers being produced on fewer tools, any downtime (due to reliability, chamber matching activity, etc.) significantly increases the risk and severity of production flow and line balance impacts vs. conventional tools. Additionally, as noted by Intel’s Sunit Rikhi at SEMI’s 2007 Industry Strategy Symposium, the deposition thickness tolerances are tightening and conventional process results may not provide adequate thickness control at the 45 and 32 nm technology nodes. For these nodes, Advanced Process Control (APC) will likely be required. To eliminate CVD tool downtime due to chamber matching activity, APC loops and out-of-specification processing, fast time-todetection with the ability to immediately feedback the thickness results is required. Because of the multiple positions within and between process chambers in the cluster, every wafer measurement is required to control the process performance.
Tevet’s Integrated Metrology Uniquely Positioned to Meet High Throughput CVD Demands.
Tevet’s Trajectory series IMM products became established in the CVD and PECVD segment prior to the recent introduction of the high throughput process tools. Tevet now believes that with the new deposition tools phasing, customer adoption of IMM will become much more widespread with a great majority of customers using IMM immediately for excursion control and later increasingly for enabling APC as the industry transitions to the advanced technology nodes.
About Tevet:
Tevet Process Control Technologies serves the semiconductor industry with unique integrated metrology solutions for critical process control challenges. Supporting customers worldwide, Tevet develops its technology and products in its headquarters in Israel and provides sales, marketing and technical support through its US offices. More information is available at www.tevet-pct.com.
Tevet’s Trajectory series integrated metrology is built upon a unique patent pending parallel sensor architecture. With multiple sensors positioned in the IMM above the wafer, the Trajectory series IMM can simultaneously measure multiple sites (usually nine; site number and position is configurable) covering more than 100X the wafer area vs. conventional small spot techniques. The Trajectory series IMM measures and completes calculations within 2 seconds per wafer enabling throughputs of over 300 wph with optimized CVD tool wafer routing sequences and robot speeds. With no moving parts required for measurement, the Trajectory series IMM provides measurement without reliability risk to the high throughput CVD cluster. Tevet’s proprietary IsTMS algorithms enable measurement in die areas with output of thickness for deposited layers as well as measurement of under-layers in complex stacks. These data are sent to the CVD tool and the fab HOST computer for dispensation on excursions and for input to APC engines to optimize chamber matching and tighten thickness distribution limits. |
