Browse Prior Art Database

Detection of Discontinuities and the Separation at an Interface of the Polysilicon Oxide

IP.com Disclosure Number: IPCOM000084049D
Original Publication Date: 1975-Sep-01
Included in the Prior Art Database: 2005-Mar-02
Document File: 2 page(s) / 33K

Publishing Venue

IBM

Related People

Pugacz-Muraszkiewicz, I: AUTHOR

Abstract

This description is directed to the use of an alkaline solution which can be used for etching heavily doped P-type silicon at room temperature from beneath an overlying porous oxide layer.

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Detection of Discontinuities and the Separation at an Interface of the Polysilicon Oxide

This description is directed to the use of an alkaline solution which can be used for etching heavily doped P-type silicon at room temperature from beneath an overlying porous oxide layer.

It has been found in multiple layer devices, especially those cases where oxide layers overlie polysilicon layers deposited on the surface of the semiconductor device, that the physical discontinuities and separation at the interfaces pose serious reliability problems, and that present methods of detection such as scanning and electron microscope detection are unsuitable, because of the configuration of the device and the various angles employed.

Shown in the figure, is a body of silicon material 10 having deposited thereon a layer of silicon dioxide 11 coated with the silicon nitride layer' 12, over which is deposited a polysilicon layer 13 which is, in turn, coated with a silicon dioxide layer 14. When the silicon dioxide layer 14 is deposited upon the polysilicon layer 13, a pin hole 17 can develop in the silicon dioxide. Also it is possible because of thermal mismatch and other problems associated with the surface of the silicon nitride layer 12, that a crack 19 can develop at the silicon dioxide-silicon nitride interface.

Such pin holes and especially such cracks as may develop between the silicon oxide layer 14 and the silicon nitride layer 12 can be detected, by etching away the unde...