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Proceedings Paper

Use of chemical sensors and process control methods to improve HF chemical etching of dielectric films in a manufacturing environment
Author(s): John L. Dolcin; V. E. Anyanwu; B. C. Chung; Clif W. Draper; Roland Ellis Jr.; A. Karp
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Paper Abstract

We report on the use of HF chemical sensors to improve the control of both 100:1 and 15:1 HF etch baths used in a bipolar technology manufacturing line. The commercial HF sensor selected for this application is based on the induction of a current from a primary coil to a secondary coil when the coils are immersed in hydrofluoric acid- water solutions. The design of the sensor is such that only polymer surfaces are exposed to the acid. The output of the sensors are used in a Wet Chemical Advisor we have developed to improve the operator control of the etch baths. We present data demonstrating how the Advisor was used to understand the sources of both episodic and drift variations to the specified bath chemistries. The use of the Wet Chemical Advisor platform has eliminated the need for process monitor wafers, and has greatly reduced the time required by operators for making up or maintaining the facilities within specifications. Historical information is stored in the PC for back reference and for quality control documentation.

Paper Details

Date Published: 16 September 1994
PDF: 8 pages
Proc. SPIE 2336, Manufacturing Process Control for Microelectronic Devices and Circuits, (16 September 1994); doi: 10.1117/12.186780
Show Author Affiliations
John L. Dolcin, AT&T Microelectronics (United States)
V. E. Anyanwu, AT&T Engineering Research Ctr. (United States)
B. C. Chung, AT&T Engineering Research Ctr. (United States)
Clif W. Draper, AT&T Engineering Research Ctr. (United States)
Roland Ellis Jr., AT&T Engineering Research Ctr. (United States)
A. Karp, AT&T Engineering Research Ctr. (United States)

Published in SPIE Proceedings Vol. 2336:
Manufacturing Process Control for Microelectronic Devices and Circuits
Anant G. Sabnis, Editor(s)

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