By Topic

Process diagnostics and thickness metrology using in situ mass spectrometry for the chemical vapor deposition of W from H2/WF6

Sign In

Cookies must be enabled to login.After enabling cookies , please use refresh or reload or ctrl+f5 on the browser for the login options.

The purchase and pricing options are temporarily unavailable. Please try again later.
5 Author(s)
Gougousi, Theodosia ; Institute for Systems Research and Department of Materials and Nuclear Engineering, University of Maryland, College Park, Maryland 20742 ; Xu, Yiheng ; Kidder, John N. ; Rubloff, Gary W.
more authors

Your organization might have access to this article on the publisher's site. To check, click on this link:http://dx.doi.org/+10.1116/1.591478 

Quadrupole mass spectrometry has been used to monitor reactant and product partial pressures in a selective W chemical vapor deposition process. A 4/1H2/WF6 molar reactant ratio was used to produce W films on Si wafers, at 67 Pa (0.5 Torr) total pressure, and for wafer temperatures around 400 °C. A relatively fast response time (∼4 s) sensor system sampled gas directly from a commercial Ulvac ERA-1000 reactor in order to minimize the effect of wall reactions. The signal from the volatile HF product, integrated over the deposition cycle, and corrected for contributions from reactions in the ion-source region of the quadrupole and for sensor drifts, was found to vary linearly with the weight of the W film deposited, to within an uncertainty of ∼7%. This provides the basis for real-time, noninvasive thickness metrology to drive process control. Depletion of both H2 and WF6 reactants was observed. The time integral of the H2 reactant depletion was also linearly related to the film weight, though the data exhibited a somewhat larger scatter due to the low conversion efficiency of the process. In addition, volatile SiF4 and SiHF3 products of the initial rapid W nucleation reaction on the Si surface were clearly observed, indicating that initial surface conditions may be monitored in real time under selective growth conditions. © 2000 American Vacuum Society.  

Published in:

Journal of Vacuum Science & Technology B: Microelectronics and Nanometer Structures  (Volume:18 ,  Issue: 3 )