Browse Prior Art Database

Temporary Elimination of Protective Diode

IP.com Disclosure Number: IPCOM000074008D
Original Publication Date: 1971-Mar-01
Included in the Prior Art Database: 2005-Feb-23
Document File: 2 page(s) / 24K

Publishing Venue

IBM

Related People

Evrenidis, P: AUTHOR [+3]

Abstract

This method allows gate oxides of MOSFET's to be tested independently from their protective diodes.

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 100% of the total text.

Page 1 of 2

Temporary Elimination of Protective Diode

This method allows gate oxides of MOSFET's to be tested independently from their protective diodes.

During certain manufacturing processes MOSFET gate oxides require the presence of a protective diode to prevent electrostatic charge breakdown of the gate oxide, as typically shown at A. MOSFET 1 is connected in parallel with the gate input 2 and protective diode 3 by interconnection line 4. In order to perform certain gate tests it is desirable to disconnect diode 3 from the gate. This may be accomplished by aligning a mask directly over the interconnection on the diode side of the circuit and etching a small break 5 in line 4 thereby disconnecting diode 3, as shown in B. After the desired tests have been performed, a second mask having a slightly larger aperture than the previous mask is used to deposit a conductive spot 6, as shown in C, preferably of the same material as conductive line 4. The spot of conductive material effectively reconnects diode 3 to the gate of MOSFET 1 due to a slight overlap between spot 6 and the broken edges of line 4.

1

Page 2 of 2

2

[This page contains 2 pictures or other non-text objects]