Laser Beam Mixing for Uniform Polysilicon Annealing
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Solution Overview
Problem
Existing laser beam annealing technologies face challenges in achieving high-quality polysilicon layers for display apparatus manufacturing, as they often result in non-uniform crystallization of amorphous silicon layers, affecting the electrical characteristics of thin-film transistors.
Innovation Solution
A laser beam annealing apparatus with a beam mixer and optical system that includes a splitter, inversion module with multiple mirrors, and a homogenizer to create a uniform intensity distribution and inverted laser beams, ensuring consistent crystallization of amorphous silicon layers into polysilicon layers.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If a conventional laser beam annealing method is used to crystallize an amorphous silicon layer, then the polysilicon layer can be formed, but the crystallization is non-uniform affecting electrical characteristics
Solution Approach 1:
The laser beam is divided into multiple beams through a beam splitter, and each beam is independently controlled to irradiate different regions of the amorphous silicon layer. This segmentation allows precise control of crystallization in each region, ensuring uniform polysilicon layer formation and consistent electrical characteristics across the entire substrate.
Solution Approach 2:
The patent uses an inversion module with mirrors to invert the laser beam image, creating a beam configuration that compensates for non-uniformities in the amorphous silicon layer deposition. By inverting the beam pattern, the system achieves uniform energy distribution and consistent crystallization results.
2Manufacturing precision
If the laser beam intensity distribution is non-uniform, then the amorphous silicon layer crystallizes unevenly, but increasing beam mixing complexity may reduce manufacturing precision
Solution Approach 1:
The optical system is designed with locally optimized components: a beam splitter for precise beam division, inversion modules with specifically arranged mirrors for targeted beam inversion, and a homogenizer positioned at the optimal location for maximum intensity uniformity. Each component addresses specific local requirements of the laser beam to achieve overall uniform polysilicon crystallization without excessive complexity.
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 apparatus achieves uniform polysilicon layer characteristics across the substrate, enhancing the electrical performance and quality of thin-film transistors in display apparatus by ensuring consistent crystallization and intensity distribution.
Implementation Method 1
a laser annealing method, in which an amorphous silicon layer is irradiated with a laser beam
Implementation Method 2
an amorphous silicon layer is crystallized to form a polysilicon layer
Data Source
AI summary
A laser beam annealing apparatus includes a laser generator which generates a first incident laser beam and a second incident laser beam, a beam mixer arranged on optical paths of the first incident laser beam and the second incident laser beam and including an inversion module which vertically and horizontally inverts an image of a laser beam, a homogenizer arranged on an optical path of a laser beam having passed through the beam mixer, and a condenser lens arranged on an optical path of a laser beam having passed through the homogenizer. The laser beam having passed through the beam mixer includes a first mixed beam in which an image is not inverted and a second mixed beam in which an image is vertically and horizontally inverted.