Polishing Apparatus Non-Integer Cycle Dressing

Solution Overview

Problem

The challenge is to uniformly dress a polishing pad using a small-sized dresser, which is difficult due to the increased size of substrates and the need to prevent a proportional increase in the size of the polishing apparatus, while ensuring efficient and uniform polishing.

Innovation Solution

A polishing apparatus with a turntable, a dresser, and a scanning mechanism that controls the rotation cycle and scanning cycle such that Ttt/Tds and Tds/Ttt are non-integers, and the relative speed and pressing force are maintained constant, allowing the dresser to scan effectively between positions on the pad.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Length of stationary object

If a small-sized dresser is used to prevent increase in polishing apparatus size, then the apparatus size is controlled, but the polishing pad uniformity deteriorates

Engineering Contradiction:

Improvepolishing apparatus sizeVSAvoidpolishing pad uniformity

Core Design Contradiction:

Length of stationary objectVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the dresser rotate at a different speed than the turntable rotation. The dresser rotation mechanism allows the dresser to rotate in the same direction as the turntable but at a different rotational speed, creating relative motion between the dresser and polishing pad. This dynamic approach enables a small dresser to cover the entire polishing pad surface over time, achieving uniform dressing without requiring a large apparatus size.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent utilizes periodic action through the coordinated rotation of the turntable and dresser at different speeds. The turntable rotates at a first rotational speed while the dresser rotates at a second rotational speed in the same direction. This periodic relative motion ensures that the dresser progressively covers different areas of the polishing pad across multiple rotation cycles, achieving complete and uniform dressing of the entire pad surface.

Inventive Principle:

Principle #19Periodic action

2Device complexity

If the dresser size is reduced, then the apparatus complexity is reduced, but the dressing coverage and uniformity worsen

Engineering Contradiction:

Improveapparatus complexityVSAvoiddressing coverage uniformity

Core Design Contradiction:

Device complexityVSManufacturing precision

Solution Approach 1:

The patent applies dynamics by making the dresser rotate at a different speed than the turntable rotation. The dresser rotation mechanism allows the dresser to rotate in the same direction as the turntable but at a different rotational speed, creating relative motion between the dresser and polishing pad. This dynamic approach enables a small dresser to cover the entire polishing pad surface over time, achieving uniform dressing without requiring a large apparatus size.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The patent applies universality by designing the dresser with multi-functionality. The dresser not only dresses the polishing pad but also rotates independently to achieve comprehensive coverage. This multi-functional design allows a single small dresser to perform the dressing function across the entire polishing pad surface, replacing what would traditionally require a larger dressing mechanism.

Inventive Principle:

Principle #6Universality (Multi-functionality)

3Length of stationary object

If a small dresser is used, then the apparatus size is controlled, but the time required for uniform dressing increases

Engineering Contradiction:

Improvepolishing apparatus sizeVSAvoiddressing time

Core Design Contradiction:

Length of stationary objectVSLoss of time

Solution Approach 1:

The patent applies continuity of useful action by maintaining continuous rotation of both the turntable and dresser during the dressing process. The dresser continuously contacts the polishing pad surface while both components rotate, ensuring uninterrupted dressing action. This continuous operation maximizes the efficiency of the small dresser, enabling it to progressively dress the entire polishing pad surface without idle periods.

Inventive Principle:

Principle #20Continuity of useful action

Solution Approach 2:

The patent utilizes periodic action through the coordinated rotation of the turntable and dresser at different speeds. The turntable rotates at a first rotational speed while the dresser rotates at a second rotational speed in the same direction. This periodic relative motion ensures that the dresser progressively covers different areas of the polishing pad across multiple rotation cycles, achieving complete and uniform dressing of the entire pad surface.

Inventive Principle:

Principle #19Periodic action

Data Source

PatentUS9962804B2Polishing apparatus, method for controlling the same, and method for outputting a dressing condition

Publication Date: 2018.05.08 EBARA CORP

AI summary

A polishing apparatus includes: a turntable for supporting a polishing pad; a turntable rotation mechanism configured to rotate the turntable; a dresser configured to dress the polishing pad; and a scanning mechanism configured to cause the dresser to scan between a first position and a second position on the polishing pad, wherein Ttt/Tds and Tds/Ttt are a non-integer where the Ttt is a rotation cycle of the turntable during dressing, and the Tds is a scanning cycle during which the dresser scans between the first position and the second position.