Coating Developing Apparatus Post-Exposure Delay Time Control

Resolve Bottlenecks,
Find Innovative SolutionsGenerate Solutions

Solution Overview

Problem

In semiconductor manufacturing, the post-exposure delay time from light exposure to post-exposure baking in photolithography processes is inconsistent due to variations in transfer arm operations, leading to poor line width uniformity and requiring additional post-exposure baking units during immersion light exposure, which increases costs.

Innovation Solution

A coating/developing apparatus with a control section that sets substrates on standby at relay and waiting positions within post-exposure baking units, using a dual transfer mechanism to manage the post-exposure delay time, ensuring consistency without increasing the number of post-exposure baking units.

Engineering Contradictions & Design Principles

VSEngineering Contradiction Analysis

1Ease of operation

If a transfer arm is used for substrate transfer between light exposure apparatus and post-exposure baking unit, then substrate transfer is enabled, but the post-exposure delay time becomes inconsistent

Engineering Contradiction:

Improvesubstrate transfer capabilityVSAvoidpost-exposure delay time consistency

Core Design Contradiction:

Ease of operationVSManufacturing precision

Solution Approach 1:

The transfer system is segmented into two independent transfer mechanisms: a first transfer mechanism for transferring substrates between the process section and light exposure apparatus, and a second transfer mechanism for transferring substrates within the interface section. This segmentation allows independent optimization of each transfer path, enabling consistent post-exposure delay time while maintaining transfer capability.

Inventive Principle:

Principle #1Segmentation

Solution Approach 2:

A relay position is introduced as an intermediary between the first and second transfer mechanisms. The relay position serves as a buffer that decouples the transfer operations, allowing the system to maintain consistent timing by providing a stable intermediate holding point for substrates during the transfer process.

Inventive Principle:

Principle #24Intermediary (Mediator)

2Manufacturing precision

If waiting time is extended to make post-exposure delay time constant, then line width uniformity is improved, but throughput decreases

Engineering Contradiction:

Improveline width uniformityVSAvoidthroughput

Core Design Contradiction:

Manufacturing precisionVSProductivity

Solution Approach 1:

The system dynamically adjusts the waiting time at the relay position based on the actual transfer time. By making the waiting time variable rather than fixed, the system can compensate for transfer time variations without requiring excessive waiting time, thus maintaining line width uniformity while minimizing throughput impact.

Inventive Principle:

Principle #15Dynamics

Solution Approach 2:

The control section monitors the actual transfer time and uses this feedback to adjust the waiting time at the relay position. This closed-loop control ensures that the post-exposure delay time remains constant despite variations in transfer operations, achieving line width uniformity without excessive waiting time that would reduce throughput.

Inventive Principle:

Principle #23Feedback

3Manufacturing precision

If additional post-exposure baking units are added to handle immersion light exposure, then post-exposure delay time consistency is achieved, but apparatus complexity and cost increase

Engineering Contradiction:

Improvepost-exposure delay time consistencyVSAvoidnumber of post-exposure baking units

Core Design Contradiction:

Manufacturing precisionVSDevice complexity

Solution Approach 1:

The relay position is designed to serve multiple functions: it acts as a transfer point between mechanisms, a waiting position for timing control, and a buffer for decoupling operations. This multi-functionality allows the system to achieve consistent post-exposure delay time without requiring additional dedicated post-exposure baking units, reducing apparatus complexity and cost.

Inventive Principle:

Principle #6Universality (Multi-functionality)

4Productivity

If transfer operations are optimized for speed, then throughput is improved, but post-exposure delay time consistency deteriorates

Engineering Contradiction:

ImprovethroughputVSAvoidpost-exposure delay time consistency

Core Design Contradiction:

ProductivityVSManufacturing precision

Solution Approach 1:

The system performs preliminary actions by having substrates wait at the relay position before entering the post-exposure baking unit. This preliminary waiting period allows the system to synchronize transfer operations with the required post-exposure delay time, ensuring consistency even when transfer operations are optimized for speed.

Inventive Principle:

Principle #10Preliminary action

Data Source

PatentUS7563043B2Coating/developing apparatus and substrate transfer method

Publication Date: 2009.07.21 TOKYO ELECTRON LTD

AI summary

In a coating/developing apparatus, a process section includes post-exposure baking units each having a waiting position and configured to perform a baking process on a substrate. An interface section transfer mechanism includes a first transfer mechanism configured to transfer the substrate to and from the process section and to load the substrate into the post-exposure baking units, and a second transfer mechanism configured to transfer the substrate to and from the light exposure apparatus. An interface section includes a relay position configured to place thereon the substrate transferred by the second transfer mechanism, and to allow the first transfer mechanism to receive the substrate therefrom. A control section is arranged to set the substrate on standby at the relay position and the waiting position, to make a time period constant among substrates from an end of the light exposure process to a start of a post-exposure baking process.