Browse Prior Art Database

Self-Aligned Passivation Process for Non-Self-Passivating Conductors

IP.com Disclosure Number: IPCOM000061268D
Original Publication Date: 1986-Jul-01
Included in the Prior Art Database: 2005-Mar-09
Document File: 2 page(s) / 25K

Publishing Venue

IBM

Related People

Abernathey, JR: AUTHOR [+3]

Abstract

A method is described for passivating conductive refractory metal lines, e.g., molybdenum with insulating materials, such as silicon nitride (Si3N4). The lines are passivated using a self-aligned technique that does not rely on thermal oxidation. As shown in the figure, a silicon substrate 2 is overlaid with a thin insulating film 4, e.g., Si3N4 . A blanket layer of a non-self-passivating conductor M is deposited, followed by deposition of a layer 6 of Si3N4 . The insulator 6 and the conductor M are then photo patterned and anisotropically etched to form conductive lines, and the photoresist is then stripped. This standard set of process steps results in the rectangular cross-section of conductive line M having insulator on its upper surface. Note that the vertical sidewalls of the conductor M are unprotected.

This text was extracted from a PDF file.
At least one non-text object (such as an image or picture) has been suppressed.
This is the abbreviated version, containing approximately 67% of the total text.

Page 1 of 2

Self-Aligned Passivation Process for Non-Self-Passivating Conductors

A method is described for passivating conductive refractory metal lines, e.g., molybdenum with insulating materials, such as silicon nitride (Si3N4). The lines are passivated using a self-aligned technique that does not rely on thermal oxidation. As shown in the figure, a silicon substrate 2 is overlaid with a thin insulating film 4, e.g., Si3N4 . A blanket layer of a non-self-passivating conductor M is deposited, followed by deposition of a layer 6 of Si3N4 . The insulator 6 and the conductor M are then photo patterned and anisotropically etched to form conductive lines, and the photoresist is then stripped. This standard set of process steps results in the rectangular cross-section of conductive line M having insulator on its upper surface. Note that the vertical sidewalls of the conductor M are unprotected. Next, a conformal coating process, e.g., chemical vapor deposition, is used to deposit a film layer 8d of Si3N4 . The dashed line indicates the location of the top surface of layer 8d after the deposition. Finally, an anisotropic etch is used to remove the thickness of insulator film 8d which is deposited on all surfaces coplanar to the substrate, leaving only the portion 8r on the vertical edges of films 6 and M. Thus, using a two-step deposition process and only one photomask, a non-self-passivating conductor may be passivated using Si3N4 . Note that other materials, such as silicon diox...