Browse Prior Art Database

PROBING TECHNIQUE FOR 1m GEOMETRIES

IP.com Disclosure Number: IPCOM000036663D
Original Publication Date: 1989-Oct-01
Included in the Prior Art Database: 2005-Jan-29
Document File: 2 page(s) / 13K

Publishing Venue

IBM

Related People

Ilker, HF: AUTHOR

Abstract

Disclosed is a technique used to electrically probe very small contacts (1 m or less) at close spacings to each other. Proper sample preparation, a specific testing sequence, and the capability to see the contacts clearly while placing the probes on them, are all required to be successful.

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PROBING TECHNIQUE FOR 1m GEOMETRIES

Disclosed is a technique used to electrically probe very small contacts (1 m or less) at close spacings to each other. Proper sample preparation, a specific testing sequence, and the capability to see the contacts clearly while placing the probes on them, are all required to be successful.

Normal sample preparation and probing techniques yield incomplete data due to the small contact size, floor and wall tremors, and the inability to clearly see the probe tip the moment it touches the metal.

These difficulties can be overcome by the following:
1. Use of a sample preparation technique which allows good

contact with the probe tips, at least one time.
2. Following a procedure which positions the probe only

one time on each small contact for all the required

electrical tests.
3. Use of objective lens on a microscope to get

approximately 1000X magnification with a working

distance of at least 20 mm.
4. Use of a probe station/air table which will isolate all

external shocks and vibrations.

Sample Preparation: Polish chip down to first metal and locate cells of interest. Continue polishing until the cell cross links are just removed for these cells. Etch the chip in glycerated buffered hydrofluoric acid solution (5:1) for approximately three minutes. This will expose the contacts so probes can make a better contact. The etch time can be varied for best results. If etch time is too long, studs may bend over and short out the base and collector contacts when probed. If etch time is too short, insufficient metal is exposed and probes will not make good contact. Rinse chip well in D.I. water and thoroughly dry. Probing Procedure...