Laser-Based Alignment Mark Formation on Semiconductor Wafers
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Solution Overview
Problem
The photolithography process for forming alignment marks in semiconductor manufacturing is costly and time-consuming, requiring multiple procedures such as photoresist coating, baking, exposing, and etching, which complicates the alignment process and increases manufacturing costs.
Innovation Solution
A photolithography-free process using a laser-based method where a laser beam is homogenized, split, and shaped to directly form alignment marks on a semiconductor wafer without the need for photoresist or etching solutions, simplifying the manufacturing process and reducing costs.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If photolithography process is used to form alignment marks, then alignment marks can be formed with good precision, but the manufacturing cost increases and the process becomes complex
Solution Approach 1:
The patent extracts the alignment mark formation step from the traditional photolithography process. By using direct laser writing, the alignment marks are formed independently without requiring photoresist coating, baking, exposing, and etching procedures. This separation eliminates the complex multi-step photolithography process while maintaining alignment mark precision through direct laser ablation on the semiconductor wafer surface.
Solution Approach 2:
The patent replaces the chemical-based photolithography system with a laser-based direct writing system. Instead of using photoresist chemicals, UV exposure, and wet etching, the invention uses focused laser beams to directly ablate and form alignment marks on the wafer surface. This substitution eliminates the need for chemical processing steps while achieving the same alignment functionality.
2Manufacturing precision
If photolithography process is used to form alignment marks, then alignment marks can be formed with good precision, but the manufacturing time increases
Solution Approach 1:
The patent performs preliminary action by directly forming alignment marks on the semiconductor wafer before subsequent processing steps. The laser-based method creates the alignment marks in a single step without requiring prior photoresist application or subsequent etching steps. This preliminary formation approach eliminates multiple time-consuming process steps while ensuring the alignment marks are precisely formed at the required locations.
Solution Approach 2:
The patent skips the intermediate steps of photolithography (photoresist coating, baking, exposing, developing, and etching) and rushes directly to forming the alignment marks using laser ablation. This skipping of unnecessary intermediate steps significantly reduces the total manufacturing time while maintaining the precision of alignment mark formation through direct laser writing on the wafer surface.
3Manufacturing precision
If photolithography process is used to form alignment marks, then alignment marks can be formed, but the manufacturing cost increases
Solution Approach 1:
The patent uses a disposable-free approach by eliminating the need for expensive photoresist materials, chemical etchants, and specialized photolithography equipment. The laser-based direct writing method uses only the laser system and control software, removing the cost of consumable chemicals and photoresist coatings. This substitution with a simpler, material-free process significantly reduces manufacturing costs while maintaining alignment mark precision.
Solution Approach 2:
The patent replaces the expensive chemical-based photolithography system with a laser-based direct writing system. By eliminating photoresist materials, chemical baths, and specialized photolithography tooling, the invention reduces material and equipment costs. The laser system provides a cost-effective alternative that achieves the same alignment functionality without the high costs associated with traditional photolithography processes.
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 method simplifies the formation of alignment marks, reduces manufacturing costs, and enhances the alignment process by eliminating the need for photolithography, while ensuring the alignment marks provide accurate alignment functionality.
Implementation Method 1
A laser beam is homogenized
Implementation Method 2
the laser beam is divided into a plurality of laser beams separated from each other
Implementation Method 3
the plurality of laser beams is shaped into a plurality of patterned beams, so that the plurality of patterned beams is shaped with patterns corresponding to alignment marks
Implementation Method 4
the plurality of patterned beams is projected onto a semiconductor wafer
Data Source
AI summary
An apparatus and a method for forming alignment marks are disclosed. The method for forming alignment marks is a photolithography-free process and includes the following operations. A laser beam is provided. The laser beam is divided into a plurality of laser beams separated from each other. The plurality of laser beams is shaped into a plurality of patterned beams, so that the plurality of patterned beams is shaped with patterns corresponding to alignment marks. The plurality of patterned beams is projected onto a semiconductor wafer.