CMP Polishing Pad Rsk Conditioning for Scratch Reduction

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Solution Overview

Problem

The existing manufacturing processes for semiconductor devices, particularly in chemical mechanical polishing (CMP), often result in scratches on the silicon oxide film due to the surface state of the polishing pad, leading to yield and reliability issues.

Innovation Solution

A manufacturing method that involves conditioning the polishing pad to achieve a negative Rsk value and adjusting the friction dependency on polishing speed to prevent stick slip, thereby reducing scratches on the polish target film during the CMP process.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Reliability

If conventional CMP process is used with standard polishing pad, then polishing function is provided, but scratches occur on the polish target film surface

Engineering Contradiction:

Improvescratch-free surface qualityVSAvoidsurface scratches

Core Design Contradiction:

ReliabilityVSObject-affected harmful factors

Solution Approach 1:

The invention changes the surface roughness parameter of the polishing pad by controlling the Rsk value to be negative. This parameter change in the polishing pad's surface morphology prevents stick-slip phenomenon during CMP, thereby eliminating scratches on the polish target film while maintaining effective polishing

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention applies preliminary conditioning treatment to the polishing pad before actual polishing to establish a negative Rsk surface roughness. This preliminary action prepares the polishing pad surface to prevent stick-slip phenomenon before it can occur during polishing, thus preventing scratches in advance

Inventive Principle:

Principle #9Preliminary anti-action

2Productivity

If polishing pad surface is not conditioned properly, then polishing process is simple, but yield and reliability deteriorate due to scratches

Engineering Contradiction:

Improvemanufacturing yieldVSAvoidsurface quality reliability

Core Design Contradiction:

ProductivityVSReliability

Solution Approach 1:

The invention introduces feedback control by measuring the Rsk value of the polishing pad surface and adjusting the conditioning process accordingly. This ensures the polishing pad maintains the optimal negative Rsk range, preventing scratches and ensuring high yield and reliability in semiconductor manufacturing

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If friction dependency on polishing speed is not controlled, then CMP process is straightforward, but stick slip occurs causing scratches

Engineering Contradiction:

Improvesurface finish precisionVSAvoidstick slip phenomenon

Core Design Contradiction:

Manufacturing precisionVSObject-generated harmful factors

Solution Approach 1:

The invention changes the friction characteristics by controlling the polishing pad's Rsk parameter. This parameter change adjusts the friction dependency on polishing speed to a range that prevents stick-slip phenomenon, achieving precise surface finish without scratches

Inventive Principle:

Principle #35Parameter changes

Solution Approach 2:

The invention replaces direct control of polishing speed and friction forces with indirect control through the Rsk parameter of the polishing pad. By substituting mechanical control with material property control, the system achieves stable friction characteristics that prevent stick-slip phenomenon

Inventive Principle:

Principle #28Mechanics substitution (Replace mechanical system)

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 minimizes scratches on the semiconductor device surfaces, enhancing yield and reliability while also prolonging the service life of the polishing pad and reducing costs.

Implementation Method 1

chemical mechanical polishing (CMP)... bringing a surface of the polish target film into contact with a surface of a polishing pad... to polish the polish target film

Methodology Applied

Scientific EffectAbrasion: Abrasion

Implementation Method 2

adjusting friction dependency on polishing speed between the polish target film and the polishing pad

Methodology Applied

Scientific EffectFriction: Friction

Data Source

PatentUS9174322B2Manufacturing method of semiconductor device

Publication Date: 2015.11.03 KIOXIA CORP

AI summary

In accordance with an embodiment, a manufacturing method of a semiconductor device includes forming a polish target film on a substrate and conducting a CMP process for the polish target film. The conducting the CMP process includes bringing a surface of the polish target film into contact with a surface of a polishing pad with a negative Rsk value, and adjusting friction dependency on polishing speed between the polish target film and the polishing pad to a value that restrains the occurrence of a stick slip to polish the polish target film.