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In-Situ Temperature Monitoring in Rtp by Acoustical Techniques

Published online by Cambridge University Press:  21 February 2011

F.L. Degertekin
Affiliation:
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305-4085
J. Pei
Affiliation:
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305-4085
Y.J. LEE
Affiliation:
Semiconductor Process and Design Center, Texas Instruments, Dallas, Texas 75265
B.T. Khuri-Yakub
Affiliation:
E. L. Ginzton Laboratory, Stanford University, Stanford, CA 94305-4085
K.C. Saraswat
Affiliation:
Center for Integrated Systems, Stanford University, Stanford, CA 94305-4085
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Abstract

A new technique utilizing the high sensitivity of acoustic wave velocity to temperature is used to measure the wafer temperature in RTP. Acoustic energy is coupled to a Lamb wave mode in the wafer using the quartz support pins already present in most rapid thermal processors. The tips of the pins are sharpened to have point contact with the wafer and acoustic transducers are bonded to the other end to excite and detect acoustic waves. By measuring the pin-to-pin time of flight of Lamb waves, it is possible to monitor the wafer temperature in-situ in the 20 - 1000°C range with ±5°C accuracy. Increasing SNR to 50dB by spring loading the pins and using better electronics, it is possible to improve this figure to ±1°C. Also a modified system with multiple spring loaded pins is constructed and wafer temperature mapping is performed using tomographic reconstruction techniques. The resulting images are in good agreement with thermocouple readings and can be used for temperature control and rapid thermal processor design.

Type
Research Article
Copyright
Copyright © Materials Research Society 1993

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References

REFERENCES

1. Peters, L., Semiconductor International, 8, pp. 5662 (1991).Google Scholar
2. Bollmann, D. and Haberger, K., Microelectronic Engineering, 19, pp. 383386 (1992).Google Scholar
3. Skimmin, H. J., J. Appl. Phys., 24 (8), pp. 988997, (1953).Google Scholar
4. Auld, B. A., Acoustic Fields and Waves in Solids, (John Wiley & Sons 1973) Vol. 1, pp. 163165.Google Scholar