Elastic Film Pressure Chamber Release for CMP Substrates
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Solution Overview
Problem
Existing substrate polishing methods, particularly in CMP apparatuses, face challenges in efficiently releasing substrates from elastic films without applying excessive stress, which can lead to substrate damage.
Innovation Solution
The method involves a substrate holding apparatus with a top ring body and an elastic film having concentric pressure chambers. By sequentially depressurizing the pressure chambers from outer to inner, and using a fixed-amount gas supply to pressurize the elastic film, the substrate is released from the elastic film with reduced stress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the substrate is released by conventional methods from the elastic film, then the substrate can be removed, but excessive stress is applied to the substrate which can lead to substrate damage
Solution Approach 1:
The pressure chambers are divided into multiple segments (first, second, third pressure chambers) arranged in a specific pattern. By independently controlling the pressure in each segment, the substrate is released in a controlled manner that distributes stress evenly, preventing localized stress concentration that could damage the substrate.
Solution Approach 2:
Different regions of the elastic film are subjected to different pressure conditions. The first, second, and third pressure chambers are pressurized or depressurized independently to create localized pressure differences that facilitate gentle, controlled substrate release without applying excessive stress to any single area.
2Manufacturing precision
If the substrate is held firmly by the elastic film during polishing, then polishing pressure is maintained, but releasing the substrate becomes difficult and may cause damage
Solution Approach 1:
The system dynamically adjusts the pressure in different pressure chambers during the polishing and release cycles. During polishing, all chambers are pressurized to hold the substrate firmly for high-quality polishing. During release, the chambers are depressurized in a controlled sequence, making the substrate easy to remove without damage.
Solution Approach 2:
The pressure chambers undergo periodic pressurization and depressurization cycles. The first, second, and third pressure chambers are pressurized during polishing to maintain substrate contact, then depressurized in sequence during release. This periodic action allows the system to switch between firm holding and easy release states.
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 method allows for the reliable and stress-reduced release of substrates from elastic films, preventing potential damage and improving the efficiency of the substrate polishing process.
Implementation Method 1
the substrate is pressed against the polishing pad by a pressurized fluid being supplied into a pressure chamber of the membrane
Implementation Method 2
the polishing head releases holding of the substrate by the membrane, remove (releases) the substrate
Data Source
AI summary
Provided is a method for releasing a substrate adsorbed to a first surface of an elastic film included in a substrate holding apparatus of a substrate polishing apparatus,a plurality of concentric pressure chambers being formed between a top ring body included in the substrate holding apparatus and a second surface of the elastic film, the method including:a first step of supplying fixed-amount gas to two or more pressure chambers among the plurality of pressure chambers to pressurize the elastic film; anda second step of sequentially depressurizing the plurality of pressure chambers from outer pressure chambers.