NMP Strip of Photoresist After Cf4-H2 RIE Etch
Original Publication Date: 1985-Dec-01
Included in the Prior Art Database: 2005-Feb-19
A reactive ion etching (RIE) technique is provided using a carbon tetrafluoride (CF4) and hydrogen gas etching process followed by a solvent, N-methyl-pyrrolidone (NMP), stripping a photoresist wherein near the completion of the etching process the flow of the hydrogen gas is turned off so as to etch off with the carbon tetrafluoride an NMP- insoluble polymerized surface of the photoresist. As indicated in the figure, a P- semiconductor substrate 10 has an N- epitaxial layer 12 grown thereon, at the interface of which is disposed an N+ subcollector region 14. AP type diffusion region 16 is formed at the surface of epitaxial layer 12. A silicon dioxide layer 18 and a silicon nitride layer 20 are provided over epitaxial layer 12.