Wafer Carrier Guide Member for Positional Deviation Control
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Solution Overview
Problem
Conventional carrier methods for large wafers, such as 450 mm wafers, face challenges with positional deviation during handling, which affects alignment and throughput in lithography processes, and existing exposure methods are not optimized for high-resolution and efficient processing of larger substrates.
Innovation Solution
A carrier method that supports wafers from below with a vertically movable support member and holds them non-contactedly from above with a suction member, ensuring precise positioning and flatness during transfer to a holding device, and an exposure method that uses energy beams to form patterns on the wafers with improved alignment and throughput.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Ease of operation
If a Bernoulli chuck is used to hold the wafer in a non-contact manner, then the wafer can be held without contact, but positional deviation exceeds permissible range during carry-in
Solution Approach 1:
A guide member is introduced as an intermediary component between the wafer and the Bernoulli chuck. The guide member has a guide hole that fits over the wafer's outer periphery, providing mechanical guidance and constraint during the carry-in operation. This intermediary structure enables the wafer to be held non-contactedly by the Bernoulli chuck while simultaneously maintaining positional accuracy through the guide member's geometric constraints.
2Productivity
If the wafer size is increased to 450 mm, then the number of dies output per wafer increases, but the wafer strength becomes much weaker
Solution Approach 1:
The support function is segmented into two independent systems: an outer periphery support structure (guide member) that provides mechanical strength and positional guidance, and a central non-contact holding system (Bernoulli chuck) that maintains wafer flatness. This segmentation allows the large 450 mm wafer to be handled with adequate support for its weakened structure while maintaining the benefits of non-contact holding for the active processing area.
3Device complexity
If conventional carrier methods are used for 450 mm wafers, then the handling process is simple, but positional deviation affects alignment measurement
Solution Approach 1:
The guide member serves as a mediator that bridges the simple mechanical handling approach with the precision requirements of alignment measurement. By providing a fixed geometric relationship between the wafer and the holding device through the guide hole and guide member interface, the system maintains measurement precision without significantly complicating the overall carrier mechanism.
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
The solution enables precise and reproducible wafer handling without positional deviation, maintaining high flatness and improving the throughput and resolution of exposure processes for larger substrates, enhancing the efficiency of device manufacturing.
Implementation Method 1
the object is held in a non-contact manner from above by a suction member
Data Source
AI summary
An exposure apparatus exposes a substrate with illumination light via an optical system. A detection system supported in a measurement station detects a mark of the substrate. A stage disposed below the optical system and the detection system holds the substrate with a holder. A carrier system has a first support member supporting the substrate in a noncontact manner and carries the substrate to a loading position in the measurement station. A second support member supports the substrate supported by the first support member, from a rear surface side of the substrate and is vertically movable independently from the first support member. A drive device relatively moves the first support member, the second support member and the holder at least in a vertical direction, at the loading position where the stage is placed. The substrate is carried from the carrier system to the holder via the first support member.