Browse Prior Art Database

Localization of Breakdown Regions in Schottky Diodes

IP.com Disclosure Number: IPCOM000083210D
Original Publication Date: 1975-Apr-01
Included in the Prior Art Database: 2005-Mar-01
Document File: 2 page(s) / 34K

Publishing Venue

IBM

Related People

Bohg, A: AUTHOR

Abstract

A technique is described that permits localizing the breakdown regions in Schottky barrier diodes. To this end, the substrate is selectively thinned from its rear side, and the diode is reverse biased until electroluminescence occurs under the Schottky contact. The electrical performance of the diode is not affected by this method.

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 96% of the total text.

Page 1 of 2

Localization of Breakdown Regions in Schottky Diodes

A technique is described that permits localizing the breakdown regions in Schottky barrier diodes. To this end, the substrate is selectively thinned from its rear side, and the diode is reverse biased until electroluminescence occurs under the Schottky contact. The electrical performance of the diode is not affected by this method.

The Schottky barrier diode of the example consists of a p- substrate 1, an n- epitaxial layer 2, an n+ buried layer 3, and a p+ isolation region 4. Through contact windows 5 and 6 in an isolation layer 7 a Schottky contact 8 is established to n- epitaxial layer 2. whereas ohmic contact 9 is connected to an n+ contact region 10.

From the wafer (or chip) to be tested a sample is ultrasonically punched out, in such a manner that the diode is disposed approximately in the center of the sample. The substrate 1 is then thinned from the rear side. The figure shows the neighborhood of the Schottky contact, and it is easy to recognize that the electric function is not affected by the preparation.

The sample is fixed in between two light microscopes, one of which serves to adjust point contacts on the inlet lines and the other being used to observe the Schottky contact. The reserve biased diode is subjected to a suitably high current. The breakdown regions are made visible by electroluminescence.

The causes for too low-breakdown voltages can be determined by high- resolution instruments.

1

Pag...