Method for generating a sunken oxide

US4888301A · kind A · utility

Assignee

• Siemens Aktiengesellschaft · DE

Inventors

• Hansjoerg Reichert · Munich, DE
• Ludwig Scharf · Munich, DE
• Heidemarie Goedecke · Munich, DE
• Herbert Weidlcih · Sauerlach, DE

Key dates

• Filing date: Sep 16, 1988
• Grant date: Dec 19, 1989
• Expiry date: Sep 16, 2008

Classification

• Technology area (CPC H): Electricity
• CPC primary: H01L21/76205
• WIPO field: Semiconductors
• WIPO sector: Electrical engineering

Abstract

A method for producing a recessed oxide allows the fabrication of large bonding pads with small capacitance. These bonding pads on simultaneously thick oxide on the semiconductor surface enable contact exposure with good image formation of fine structures on the surface of a transistor. With a protective layer (2), a region (S1) of a semiconductor surface (1) is covered. The area of the semiconductor surface (1) uncovered with the protective layer (2) is etched. Subsequently, an oxide (3) of desired thickness (b) is deposited. With a second phototechnological step the deposited oxide (3) is etched with a structure (S2). Thermal oxidation follows with growth of a hermetic oxide layer (4) the thickness (c) of which is small relative to the thickness (b) of the deposited oxide layer (3). The thermic oxide layer (4) is structured to form the desired geometry.