Dishing Prevention Layer for Semiconductor CMP Uniformity
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Solution Overview
Problem
Chemical Mechanical Polishing (CMP) techniques often result in dishing, a nonuniform thickness profile, when planarizing structures with wide dimensions such as large metal pads or wide trenches, leading to undesirable thickness variations in semiconductor manufacturing.
Innovation Solution
A method involving the formation of a dishing prevention layer or layer stack, which conforms to a recess in the isolation region, is used to minimize dishing by planarizing the fill layer or layer stack within the recess while stopping on the isolation region outside the recess, thereby maintaining a uniform thickness.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a recess is formed in the isolation region and filled with semiconductor or metal material, then dishing is prevented, but device complexity increases
Solution Approach 1:
The patent merges multiple functions into the recess structure: it serves as both a dishing prevention mechanism and a substrate for forming electrical contacts or devices. By combining these functions into a single structural feature, the patent reduces overall device complexity compared to implementing separate dishing prevention structures and contact structures.
Solution Approach 2:
The recess structure serves multiple purposes: preventing dishing during CMP, providing a confined area for fill material deposition, and serving as a substrate for forming electrical contacts or active/passive devices. This multi-functionality reduces the need for additional separate structures, thereby simplifying the overall device design and reducing complexity.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
This approach effectively reduces or prevents dishing, ensuring a more uniform thickness and minimizing post-planarization residue, allowing for the formation of active or passive devices within the recessed semiconductor structure.
Implementation Method 1
Chemical Mechanical Polishing/Planarization (CMP) is a technique widely employed in semiconductor manufacturing for planarizing a first layer
Data Source
AI summary
A method of manufacturing a semiconductor device includes: forming an isolation region comprising a dielectric material on a substrate; forming a recess in the isolation region, wherein a thickness of the isolation region is reduced but greater than zero in the recess; forming a fill layer or layer stack including at least one of a semiconductor or metal on the isolation region and which conforms to the recess; forming a dishing prevention layer or layer stack on the fill layer or layer stack and which conforms to the recess; planarizing the dishing prevention layer or layer stack and the fill layer or layer stack to confine the dishing prevention layer or layer stack and the fill layer or layer stack to the recess, wherein the planarizing stops on the isolation region outside the recess; and forming one or more electrical contacts to the fill layer or layer stack confined to the recess.