Polishing Pad Abrasion Measurement Using Elevating Mechanism
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Solution Overview
Problem
Existing Chemical Mechanical Polishing (CMP) apparatuses lack a simple structure for measuring the abrasion amount of polishing pads, leading to increased size and complexity due to the requirement for dedicated space and equipment.
Innovation Solution
A substrate processing apparatus with a table, pad holder, elevating mechanism, and abrasion amount measurement member that lowers the polishing pad to measure abrasion based on the behavior of the elevating mechanism until it contacts a reference surface, allowing for accurate and simple abrasion measurement without additional complex configurations.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If a contact stylus displacement meter is used to measure polishing pad thickness, then measurement precision is improved, but device complexity increases due to requiring dedicated space and additional equipment
Solution Approach 1:
The elevating mechanism originally designed for polishing pad positioning is made to serve dual purposes: both positioning the polishing pad during CMP processing and measuring polishing pad abrasion. By controlling the elevating mechanism to lower the polishing pad until contact with a reference surface, the system uses the existing displacement control capability to measure abrasion amount, eliminating the need for separate measurement equipment.
Solution Approach 2:
The system uses its own elevating mechanism to perform self-diagnosis of polishing pad wear. The abrasion amount measurement is achieved by the elevating mechanism's own displacement measurement capability, without requiring external measurement devices. The system essentially measures its own state changes.
2Measurement precision
If dedicated measurement equipment is added to measure polishing pad abrasion, then measurement precision is improved, but the apparatus size increases due to requiring additional space
Solution Approach 1:
The elevating mechanism is designed to perform multiple functions including both the polishing pad positioning during CMP processing and the measurement of polishing pad abrasion. By controlling the elevating mechanism to lower the polishing pad until contact with a reference surface, the system uses the existing displacement control capability to measure abrasion amount, eliminating the need for separate measurement equipment and reducing apparatus size.
Solution Approach 2:
The abrasion measurement function is merged with the existing elevating mechanism rather than being implemented as a separate system. The displacement measurement capability that already exists for positioning purposes is repurposed to measure abrasion, combining two functions into one mechanism and avoiding additional space requirements.
3Device complexity
If a simple structure is used for abrasion measurement, then device complexity is reduced, but measurement precision may be compromised without dedicated measurement equipment
Solution Approach 1:
The system uses its own elevating mechanism to perform self-diagnosis of polishing pad wear. The abrasion amount measurement is achieved by the elevating mechanism's own displacement measurement capability, without requiring external measurement devices. The system essentially measures its own state changes, maintaining simplicity while achieving accurate measurements through proper control methodology.
Solution Approach 2:
The system implements a feedback control loop where the elevating mechanism lowers the polishing pad while monitoring displacement in real-time. When the polishing pad contacts the reference surface, the control system detects this state and stops the lowering motion. The total displacement accumulated during this process provides the abrasion measurement, ensuring accuracy through active control and feedback.
Data Source
AI summary
To measure an amount of abrasion of a polishing pad with a simple structure.A substrate processing apparatus 1000 includes: a table 100 for supporting a substrate WF with a surface to be polished facing upward; a pad holder 226 for holding a polishing pad 222 for polishing the substrate WF supported by the table 100; an elevating mechanism 260 for moving up and down the polishing pad 222 held to the pad holder 226; and an abrasion amount measurement member 270 configured to lower the polishing pad 222 by the elevating mechanism 260 and measure the amount of abrasion of the polishing pad 222 based on a value correlated with a behavior of the elevating mechanism 260 until the polishing pad contacts a reference surface.