Hostname: page-component-78c5997874-94fs2 Total loading time: 0 Render date: 2024-11-06T09:39:49.872Z Has data issue: false hasContentIssue false

In Situ Temperature Measurement During Oxide Chemical Mechanical Planarization

Published online by Cambridge University Press:  01 February 2011

Jesse Cornely
Affiliation:
Tufts University, Department of Mechanical Engineering Medford, MA 02155, U.S.A
Chris Rogers
Affiliation:
Tufts University, Department of Mechanical Engineering Medford, MA 02155, U.S.A
Vincent Manno
Affiliation:
Tufts University, Department of Mechanical Engineering Medford, MA 02155, U.S.A
Ara Philipossian
Affiliation:
University of Arizona, Department of Chemical Engineering Tucson, AZ 85721, U.S.A
Get access

Abstract

This paper presents temperature and friction force data at the pad-slurry-wafer interface during real time CMP polishing with in situ pad conditioning. Experiments are performed on a 1:2 scale laboratory tabletop rotary polisher with variable pad speed and wafer down force control. Dual emission laser induced fluorescence (DELIF) techniques are used to optically measure the temperature directly beneath the wafer during polishing using a two camera imaging system. An infrared camera and a thermocouple are alternately used to measure bow wave temperatures. Optically transparent BK-7 glass wafers with either concave (wafer edges sloping toward the pad) or convex (wafer edges sloping away from the pad) curvature were used. When concave wafers are polished, the bow wave temperatures are 3°C to 5°C higher than the corresponding value for convex wafers. Similarly, slurry temperatures under the concave wafers are 5°C to 6°C higher than the value for convex wafers (±0.5°C). The friction force per unit area is typically 2 kPa to 3 kPa higher for concave wafers. Temperatures beneath the wafer are as high as 12°C above the ambient temperature for a concave wafer at a high applied wafer pressure (41.4 kPa) or linear velocity (0.93 m/sec). Bow wave temperatures reach as high as 9°C above ambient at a linear velocity of 0.93 m/sec. The lowest temperatures, within 1°C of ambient at the bow wave and 5°C above ambient under the wafer, were found with convex wafers at low applied wafer pressures (20.7 kPa). Linear velocity has little effect on the slurry temperature while polishing convex wafers. Increasing slurry abrasive concentration causes an increase in temperature, despite a decrease in friction force. A correlation, with an R-squared value greater than 0.96, exists between the bow wave temperature and the temperature beneath the wafer. This correlation holds at constant linear velocities across wafer shapes, applied wafer pressures, and slurry concentrations.

Type
Research Article
Copyright
Copyright © Materials Research Society 2003

Access options

Get access to the full version of this content by using one of the access options below. (Log in options will check for institutional or personal access. Content may require purchase if you do not have access.)

References

1. Cornely, J. ‘Thermal Characteristics of CMP,’ M.S. Thesis, Tufts University (2003).Google Scholar
2. Cornely, J. Rogers, C. Manno, V. Philipossian, A. Dual Emission Laser Induced Fluorescence Techniques for Measuring Fluid Film Thickness and Temperature, Experiments in Fluids (2003).Google Scholar
3. Sugimoto, F, Arimoto, Y, and Ito, T. ‘Simultaneous temperature measurement of wafers in chemical mechanical polishing of silicon dioxide layer,’ Japanese Journal of Applied Physics, 34:63146320 (1995).Google Scholar
4. Li, W, Shin, D W, Tomozawa, M, and Murarka, S P. ‘The effect of the polishing pad treatments on the chemical-mechanical polishing of SiO2 films,’ Thin Solid Films, 270:601606 (1995).Google Scholar
5. Beckage, P, Lukner, R, Cho, W aand Edwards, K, Jester, M, and Shaw, S. ‘Improved metal CMP endpoint control by monitoring carrier speed controller output or pad temperature,’ Proceedings of SPIE, 3882:118125 (1999).Google Scholar
6. Fayolle, M, Sicurani, E, and Morand, Y. ‘W CMP process integration: Consumables evaluation - electrical results and end point detection,’ Microelectronic Engineering, 37/38:347352 (1997).Google Scholar
7. Wang, D, Liu, C, Feng, M S, and Tseng, W T. ‘The exothermic reaction and temperature measurement for tungsten CMP technology and its application on endpoint detection,” Materials Chemistry and Physics, 52:1722 (1998).Google Scholar
8. Hocheng, H, Huang, Y L, and Chen, I J. ‘Kinematic analysis and measurement of temperature rise on a pad in chemical mechanical planarization,’ Journal of the Electrochemical Society, 146(11):42364239 (1999).Google Scholar
9. Stein, D J and Hetherington, D L. ‘Prediction of tungsten CMP pad life using blanket removal rate data and endpoint data obtained from process temperature and carrier motor current measurements,’ Proceedings of SPIE, 3743:112119 (1999).Google Scholar
10. Coppeta, J. ‘Investigating Fluid Behavior Beneath a Wafer during CMP,’ Ph.D. Thesis, Tufts University (1999).Google Scholar
11. Lu, J. ‘Fluid Film Lubrication in CMP,’ M.S. Thesis, Tufts University (2001).Google Scholar
12. Coppeta, J. Rogers, C. Racz, L. Philipossian, A. and Kaufman, F.Investigating Slurry Transport Beneath a Wafer during CMP,’ J. Electrochem. Soc., Vol. 144, No. 5 (2000).Google Scholar
13. Rogers, C. Copetta, J. Racz, L. Philipossian, A. Baromono, D. and Kaufman, F.Analysis of Flow Between a Wafer and Pad During CMP Processes,’ Journal of Electronic Materials, Vol. 27, No. 19 (1998).Google Scholar
14. Philipossian, A. “Fluid Dynamics Considerations in CMP,’ in Proceedings of the MRS Conference, San Francisco, CA (2000).Google Scholar
15. Olsen, S. ‘Tribological and Removal Rate Characterization of ILD CMP,’ M.S. Thesis, University of Arizona (2002).Google Scholar
16. Chan, E. Private conversation.Google Scholar