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:
Aug. 23, 2005
Filed:
Jun. 21, 2000
Anand Srinivasan, Huddinge, SE;
Carl-fredrik Carlstrom, Farsta, SE;
Gunnar Landgren, Sollentuna, SE;
Anand Srinivasan, Huddinge, SE;
Carl-Fredrik Carlstrom, Farsta, SE;
Gunnar Landgren, Sollentuna, SE;
Surface Technology Systems PLC, Gwent, GB;
Abstract
A substrate whose elemental constituents are selected from Groups III and V of the Periodic Table, is provided with pre-defined masked regions. Etching of the substrate comprising the steps of: a) forming a gas containing molecules having at least one methyl group (CH) linked to nitrogen into a plasma; and b) etching the unmasked regions of the substrate by means of the plasma. For a substrate whose elemental constituents are selected from Groups II and VI of the Periodic Table, the plasma etching gas used is trimethylamine. Since the methyl compound of nitrogen has a lower bond energy than for hydrocarbon mixtures, free methyl radicals are easier to obtain and the gas is more efficient as a methyl source. In addition, compared with hydrocarbon mixtures, reduced polymer formation can be expected due to preferential formation of methyl radicals over polymer-generating hydrocarbon radicals because of the lower bond energy for the former.