The patent badge is an abbreviated version of the USPTO patent document. The patent badge does contain a link to the full patent document.
The patent badge is an abbreviated version of the USPTO patent document. The patent badge covers the following: Patent number, Date patent was issued, Date patent was filed, Title of the patent, Applicant, Inventor, Assignee, Attorney firm, Primary examiner, Assistant examiner, CPCs, and Abstract. The patent badge does contain a link to the full patent document (in Adobe Acrobat format, aka pdf). To download or print any patent click here.
Patent No.:
Date of Patent:
Jul. 27, 1993
Filed:
Dec. 03, 1990
Makoto Kosugi, Isehara, JP;
Fujitsu Limited, , JP;
Abstract
The CVD W deposition process is observed while changing the substrate temperature, with IR thermometer measurement. The temperature indicated changes with emissivity depending on the surface morphology and materials. As the response time of this measurement is short, it is possible to perform in situ observation of changing surface morphology. This is a valid method to evaluate the deposition process. On a silicon substrate, the indicated temperature increases rapidly as soon as the gas flow starts, i.e. as soon as tungsten is deposited on the substrate. The indicated temperature increases in two steps. One is for silicon reduction and the other is for hydrogen reduction. Furthermore, it is found that the start of deposition on insulators is delayed. This phenomenon is related to the selective deposition. The thickness of deposited tungsten films can on insulatars be estimated by measuring the delay time and the thickness of tungsten on silicon. The reaction process for silicon and hydrogen reduction is evaluated by this method. We found that within 10 seconds the silicon reduction was finished and the hydrogen reduction started. We also found that optimum silicon reduction enhances the selectivity.