Hostname: page-component-78c5997874-dh8gc Total loading time: 0 Render date: 2024-11-05T17:02:53.458Z Has data issue: false hasContentIssue false

Effect of Polishing Pad Material Properties on Chemical Mechanical Polishing (Cmp) Processes

Published online by Cambridge University Press:  25 February 2011

Rajeev Bajaj
Affiliation:
Sematech, 2706 Montopolis Drive, Austin, TX 78741
Mukesh Desai
Affiliation:
Center for Polymer Research, University of Texas, Austin, TX 78712 On assignment from IBM (Present address: Speedfam Corporation, Phoenix, AZ)
Rahul Jairath
Affiliation:
Center for Polymer Research, University of Texas, Austin, TX 78712 On assignment from National Semiconductor Corporation
Matthew Stell
Affiliation:
Center for Polymer Research, University of Texas, Austin, TX 78712 On assignment from Digital Equipment Corporation
Robert Tolles
Affiliation:
Center for Polymer Research, University of Texas, Austin, TX 78712
Get access

Abstract

Chemical mechanical polishing (CMP) technology has successfully met the stringent requirements of ultraplanarized surfaces in semiconductor manufacture. Commonly, polyurethane based pads have been used to achieve this level of planarization. Recent studies have shown that the material properties of polishing pads used in the CMP process strongly influence the ability to reduce topography. In addition, past work has shown that in the absence of pad regeneration, polishing rate drops dramatically with polishing time. This decrease in material removal rate is believed to coincide with deterioration of the pad surface due to “cold flow” and/or “caking” of the pad material. This study attempts to correlate the intrinsic polymer properties and cellular structure of the pad material to CMP process indices like polishing rate and planarity. For example, the drop off in removal rate as a function of time can be attributed to the mechanical response of polyurethanes under conditions of critical shear. Moreover, planarity achieved is a function of pad stiffness - which itself is dependant upon intrinsic polymer stiffness and cell density.

Type
Research Article
Copyright
Copyright © Materials Research Society 1994

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

REFERENCES

1 Jairath, Rahul, et al. , “Role of consumables in the Chemical Mechanical Planarization (CMP) of silicon dioxide films”. Proceedings of MRS conference, San Diego, March 1993.Google Scholar
2 “Cellular Materials”, Encyclopedia of Polymer Science and Engineering Vol 3, John Wiley & Sons, 1985.Google Scholar
3 Turner, Alfrey Jr., “Mechanical Behavior of High Polymers”, High Polymers vol VI, Interscience Publishers Inc., NY, 1948.Google Scholar
4 Sanders, J.H., Frisch, K.C., “Polyurethanes : Chemistry and Technology II. Technology”, Interscience Publishers Inc., NY, 1964.Google Scholar
5 Hilyard, N.C. (Editor), “Mechanics of Cellular Plastics”, MacMillan Publishing Co. Inc., NY, 1982.Google Scholar