Low-Temperature Polysilicon Thin Film Protrusion Control
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Solution Overview
Problem
The surface protrusions in low temperature polysilicon thin films, formed during the recrystallization process, affect the operating properties of transistors and decrease display quality due to their size and aspect ratio, which are not adequately addressed by existing manufacturing methods.
Innovation Solution
A method involving the formation of a buffer layer with pores and a silicon layer that includes recrystallization growth spaces, followed by annealing to reduce the size of surface protrusions, where the buffer layer's meticulous structure and surface roughening create spaces for the polysilicon material to fill, thereby controlling the protrusion size and aspect ratio.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If excimer laser annealing is used to recrystallize amorphous silicon into polysilicon, then the conductive capacity of the transistor is improved, but surface protrusions are formed that affect transistor properties and display quality
Solution Approach 1:
A buffer layer is formed on the substrate before depositing the silicon layer. This buffer layer undergoes preliminary processing (sputtering with specific power and time control) to create a controlled rough surface that will serve as a template for subsequent polysilicon growth, preventing surface protrusions during laser annealing
Solution Approach 2:
The buffer layer is created with a controlled rough surface structure through sputtering parameters. This rough surface provides nucleation sites and controls the growth morphology of the polysilicon layer during laser annealing, preventing excessive surface protrusions while maintaining good electrical properties
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 method significantly reduces the size and aspect ratio of surface protrusions to less than 0.3, improving the consistency of transistor properties and display quality by easing the crystal squeeze during recrystallization.
Implementation Method 1
the excimer laser is used as a heat source, and the laser beam irradiates the amorphous silicon thin film to make the amorphous silicon recrystallize and transform into the polysilicon structure
Implementation Method 2
the laser beam irradiates the amorphous silicon thin film to make the amorphous silicon recrystallize and transform into the polysilicon structure
Implementation Method 3
a surface of the buffer layer has a plurality of pores, and a partial silicon material of the polysilicon layer is filled into the pores
Data Source
AI summary
A method of manufacturing a low temperature polysilicon thin film, including: forming a buffer layer on a substrate; forming a silicon layer on the buffer layer; providing a mask; patterning the silicon layer through the mask, wherein the patterned silicon layer includes a plurality of recrystallization growth spaces; and annealing the silicon layer to form a polysilicon layer, and a partial silicon material of the polysilicon layer is formed on the recrystallization growth space.