Substrate Bonding Position Sensing Through a Transparent Reference
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Solution Overview
Problem
Existing substrate bonding technologies face challenges in accurately aligning and bonding substrates with precise control over the bonding process, particularly in ensuring uniform contact and efficient expansion of the bonding region from the central to peripheral portions.
Innovation Solution
A substrate processing apparatus equipped with a holder, optical sensors, and a processor to measure the distance between the substrate and a transparent member, allowing for precise alignment and bonding through a series of controlled steps involving hydrophilization, temperature adjustment, and vacuum attraction, with displacement sensors monitoring the bonding progress.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If multiple sensors are arranged along the circumferential direction of the upper chuck to detect bonding progress, then the bonding region expansion can be monitored, but the measurement precision is affected by refractive index changes when void reducing gas is introduced
Solution Approach 1:
A transparent member is introduced as an intermediary reference object in the measurement light path. The optical sensor measures the distance to this transparent member instead of directly measuring the substrate distance. This intermediary reference point is not affected by the void reducing gas, providing a stable reference that eliminates measurement errors caused by refractive index changes in the gas environment
Solution Approach 2:
The measurement approach changes from directly measuring substrate position to measuring the distance between the optical sensor and a transparent reference member. By changing the measurement parameter from substrate distance to reference member distance, the system achieves immunity to refractive index variations caused by void reducing gas introduction
2Reliability
If void reducing gas is introduced into the measurement light path to reduce edge voids during bonding, then bonding quality improves, but measurement precision deteriorates due to refractive index changes
Solution Approach 1:
The transparent member serves as a mediator that allows void reducing gas to be introduced for bonding quality improvement while providing a stable reference point for measurements. The gas can now be introduced between the transparent member and substrate without affecting the reference measurement, thus improving bonding quality while maintaining measurement precision
Solution Approach 2:
The reference measurement function is extracted from the substrate-position-dependent measurement and separated into an independent measurement of the transparent reference member. This extraction allows the void reducing gas to be introduced into the remaining light path without compromising the reference measurement stability
3Manufacturing precision
If the bonding region is expanded from central portions to peripheral portions through molecular force, then uniform bonding is achieved, but the process time increases
Solution Approach 1:
The optical sensors provide real-time feedback on substrate position and bonding progress. This feedback enables dynamic adjustment of bonding parameters, allowing the system to monitor and control the expansion of the bonding region from center to periphery, ensuring uniform bonding while optimizing process time through active control rather than passive waiting
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
Enables precise and uniform bonding of substrates by ensuring accurate alignment and controlled expansion of the bonding region, enhancing the quality and reliability of the bonded substrate.
Implementation Method 1
an optical sensor provided in the upper chuck, and configured to radiate measurement light to the substrate and receive reflection light from the substrate
Implementation Method 2
a transparent member placed in a measurement light path between the substrate and the optical sensor, and allowed to transmit light
Implementation Method 3
an upper chuck configured to attract a substrate at an upper side from above and a lower chuck configured to attract a substrate at a lower side from below
Implementation Method 4
bonds the central portions of the two substrates together by a molecular force
Data Source
AI summary
A substrate processing apparatus includes a holder for holding a substrate allowed to be separated; an optical sensor, provided in the holder, for radiating measurement light to the substrate and receive reflection light from the substrate; a transparent member placed in a measurement light path between the substrate and the optical sensor, and allowed to transmit light; and a controller for processing measurement information from the optical sensor and for acquiring a distance between the substrate and the transparent member based on the measurement information to recognize a position of the substrate.