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A Method for Fabricating a Void-free Contact

IP.com Disclosure Number: IPCOM000238194D
Publication Date: 2014-Aug-07
Document File: 5 page(s) / 107K

Publishing Venue

The IP.com Prior Art Database

Abstract

A method is disclosed for fabricating a void-free contact.

This text was extracted from a PDF file.
This is the abbreviated version, containing approximately 53% of the total text.

Page 01 of 5

A Method for Fabricating a Void-free Contact


As semiconductor device geometry continues to shrink, the aspect ratio for contacts increases. Tungsten (W) deposition into the contact often leaves a keyhole void inside the contact with the current process flow. After performing Chemical Mechanical Planarization (CMP) of tungsten in the current process flow, the keyhole void is exposed which affects a following V0 process. This keyhole significantly increases contact resistance resulting in functional failure at time zero or reliability failure. Here, the keyhole void is created in W deposition due to contact liner overhang at the very top of the portion of contact.

Disclosed is a method for fabricating a void-free contact. The method extends the current contact process flow with four new steps to get rid of the overhung liner so that there is no pinch-off during W deposition.

The method however utilizes no additional mask for fabricating the void free contact. The method increases the contact dielectrics by a small amount than the current process. Fig. 1 illustrates the step of obtaining contact opening etch with higher dielectric.

Figure 1

Fig. 2 illustrates the resultant structure from subsequent step of performing Physical Vapor Deposition (PVD) titanium (Ti) deposition with higher dielectric.

1


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Figure 2

Thereafter, Atomic Layer Deposition (ALD) Titanium Nitride (TiN) deposition is performed to obtain the structure illustrated in Fig. 3.

Figure 3

After depositi...