International Business Machines Corporation

Robert C McIntosh

Kevin K Chan

Christopher F Lyons

Zeev A Weinberg

Ming-Fea Chow

Joseph M Blum

Anthony F Scaduto

Alexander D Lopata

The present invention relates to a low-pressure chemical vapor deposition (LPCVD) process for depositing silicon dioxide. In particular, the present invention describes a process involving a pre-cleaning step in which all impurities are removed from the substrate followed by a LPCVD step performed at temperatures of between 200.degree. C. and 300.degree. C. The process of the present invention is intended to replace higher temperature LPCVD and thermal processes for depositing silicon dioxide. More particularly, the present invention involves a process in which a substrate is washed using a predetermined cleaning process. The substrate is then exposed to a dilute hydrofluoric acid solution which removes native oxide and contaminants from the surface. Next, the substrate is rinsed with, for example, de-ionized water or ultra-clean water to remove any hydrofluoric acid or other residue from the previous process steps. A layer of material, for example, silicon dioxide, is then deposited using a low-pressure chemical vapor deposition process in which the gas flow comprises silane, oxygen and nitrogen at temperatures below 300.degree. C. Oxide qualities approaching those of thermally grown oxides having been achieved.

High-throughput, low-temperature process for depositing oxides

A process for setting the exposure speed of photolithography instruments is described, using a method of dosimetry based on photoactive compound bleaching of photoresist. A curve of light absorbance to exposure speed and a calibration curve of light absorbance to dose are determined for a photoresist. The exposure speed for any desired degree of resist bleaching can be set using the first curve, and the exposure speed for a predetermined dosage can be set by determining the common light absorbance value on the exposure speed and dosage curves.

Method for dose calculation of photolithography projection printers

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Bronx, NY, United States of America

Robert C McIntosh