Semiconductor Exposure Alignment Using Intermediary Marks
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Solution Overview
Problem
In semiconductor device manufacturing, the positioning accuracy between divided pattern regions is compromised due to the limitations of existing alignment methods, particularly when patterns are exposed using a photomask that exceeds the effective exposure region of the exposure apparatus, leading to decreased accuracy in connecting divided patterns.
Innovation Solution
A method involving the formation of a first photoresist film with an alignment pattern, followed by the creation of alignment marks on the substrate, and subsequent exposure and development of a second photoresist film divided into regions, allowing for precise positioning using these marks even beyond the effective exposure region of the apparatus.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Area of stationary object
If a photomask with a pattern larger than the effective exposure region is used for divided exposure, then the chip region can be fully covered, but the positioning accuracy between divided pattern regions deteriorates due to dependence on stepping accuracy
Solution Approach 1:
The patent introduces an alignment mark as an intermediary reference object that is formed separately from the divided pattern regions. This alignment mark serves as a common reference point for positioning all divided regions, eliminating the need to rely on stepping accuracy between regions. The alignment mark acts as a mediator that enables precise positioning without direct mechanical coupling between divided regions.
Solution Approach 2:
The patent segments the exposure process into two independent parts: (1) formation of alignment marks in a first region, and (2) formation of divided patterns in a second region. This segmentation allows the alignment marks to be created with high precision in a controlled area, while the divided patterns can be exposed in separate regions using the alignment marks as references, thereby maintaining positioning accuracy across the entire chip region.
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 approach enhances the positioning accuracy between divided pattern regions by utilizing alignment marks to guide the exposure process, reducing the influence of exposure apparatus stepping accuracy and improving the connection accuracy of patterns across larger chip regions.
Implementation Method 1
exposing a first pattern including an alignment pattern on the first photoresist film
Implementation Method 2
developing the second photoresist film and forming the second photoresist film having the second pattern
Data Source
AI summary
A method of manufacturing a semiconductor device includes forming a first photoresist film over a substrate, exposing a first pattern including an alignment pattern in a first region, forming, on the substrate, an alignment mark corresponding to the exposed alignment pattern, forming a second photoresist film over the substrate on which the alignment mark is formed, dividing a second pattern into a plurality of regions and exposing the divided regions separately in a second region while performing positioning with respect to the alignment mark, and developing the second photoresist film and forming the second photoresist film having the second pattern, wherein at least a part of the second region is located outside an effective exposure region of an exposure apparatus in exposure of the first pattern.