Browse Prior Art Database

Copper Electroplate Pre-Anneal Process Optimization to Address Post Copper Polish Defects

IP.com Disclosure Number: IPCOM000019832D
Publication Date: 2003-Oct-01
Document File: 4 page(s) / 99K

Publishing Venue

The IP.com Prior Art Database

Abstract

Disclosed is a method that uses an anneal treatment on the wafer prior to electroplating to correct post-polish defects.). Benefits include improved yield and parametric performance and reliability.

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Copper Electroplate Pre-Anneal Process Optimization to Address Post Copper Polish Defects

Disclosed is a method that uses an anneal treatment on the wafer prior to electroplating to correct post-polish defects.). Benefits include improved yield and parametric performance and reliability.

Background

Currently, most processes use a rinse only pre-treatment of the barrier seed, which has inferior post CMP defect performance. It is known that pre-anneal of the barrier-seed creates copper electroplate film stability (i.e. reduces grain growth and re-crystallization).

General Description

The disclosed method uses an anneal treatment on the wafer prior to electroplating to correct post-polish defects. See Figure 1 for examples of these defects. Pre-annealing is completed after barrier seed deposition and prior to electroplating, at temperatures optimized for process [anneal conditions from no-anneal to 350C have been evaluated]. One key issue is to balance CMP defect performance versus gap fill degradation caused by over annealing the seed layer (see Figure 2). Figure 3 outlines the disclosed method’s process. Figure 4 shows post CMP defects (as viewed on an SEM) as a function of pre-anneal condition.

Advantages

Stress relaxation of electroplated copper films influences copper polish performance defects. Annealing wafers prior to electroplating is a key modulator for stress relaxation. Proper choice of pre-anneal conditions can influence post copper polish defect performance. Thi...