LTPS Array Substrate Vapor Deposition Doping
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Solution Overview
Problem
The manufacturing process of low temperature poly-silicon (LTPS) array substrates is excessively complex and costly due to the numerous processes required for doping, which involves multiple masks and equipment, increasing the overall cost and complexity.
Innovation Solution
A method is introduced that simplifies the process by forming a doped amorphous silicon thin film using vapor deposition with a gas mixture of SiH4, Ar, and H2, followed by dehydrogenation and annealing to create a polysilicon layer, which is then patterned using a masking plate with both a mask and a half-tone mask, reducing the number of masks and equipment needed while achieving homogeneous doping.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If multiple doping processes are performed with separate masks, then the doping precision and control are improved, but the device complexity and manufacturing cost increase
Solution Approach 1:
The patent combines multiple doping processes into a single vapor deposition step by introducing different dopant gases (PH3 for N-type, B2H6 for P-type) simultaneously or sequentially into the deposition chamber. This merging of processes eliminates the need for multiple separate masking and doping steps, reducing process complexity while maintaining doping precision through controlled gas flow rates and timing.
Solution Approach 2:
The vapor deposition system is designed to perform multiple functions: depositing the amorphous silicon layer and introducing dopants in a single process step. The system can switch between different dopant gases or adjust gas flow rates to achieve both N-type and P-type doping, as well as undoped regions, making the process universally applicable to different doping requirements without changing equipment or procedures.
2Manufacturing precision
If multiple masks are used for different doping steps, then the doping selectivity is improved, but the loss of time and manufacturing efficiency decrease
Solution Approach 1:
The patent introduces dopant gases during the vapor deposition process itself, before the deposition is complete. By pre-introducing the dopants into the chamber or adjusting gas flow rates during deposition, the doping occurs concurrently with layer formation, eliminating subsequent separate doping steps and reducing overall manufacturing time while maintaining selectivity through spatial or temporal control of gas introduction.
3Manufacturing precision
If traditional sequential doping processes are used, then the doping control is improved, but the productivity and manufacturing efficiency decrease
Solution Approach 1:
The vapor deposition process with in-situ dopant introduction creates a continuous manufacturing process where the amorphous silicon layer is deposited and doped in a single uninterrupted step. The process maintains continuous gas flow and deposition, eliminating the stop-start nature of sequential processes, thereby improving productivity while maintaining doping control through precise gas flow regulation and deposition parameter optimization.
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 reduces the number of manufacturing processes, decreases equipment investment, and improves the electrical properties of the LTPS array substrate by simplifying gas introduction and using fewer masks, resulting in a more efficient and cost-effective production process.
Implementation Method 1
depositing first gas mixture and doped ionized gas by using vapor deposition to form a doped amorphous silicon thin film on the buffer layer
Implementation Method 2
depositing the first gas mixture constituted by SiH4, Ar, and H2 and boron hydride or hydrogen phosphide doped ionized gas by chemical vapor deposition to form the doped amorphous silicon thin film on the buffer layer
Implementation Method 3
depositing second gas mixture by using vapor deposition to dehydrogenate the amorphous silicon thin film
Implementation Method 4
depositing the second gas mixture constituted by hydrogen phosphide or boron hydride by using chemical vapor deposition to dehydrogenate the amorphous silicon thin film
Implementation Method 5
performing an annealing treatment to the amorphous silicon thin film being dehydrogenated to diffuse dopant ions so as to form a polysilicon layer
Implementation Method 6
performing an excimer laser annealing to the amorphous silicon thin film being dehydrogenated to diffuse the dopant ions so as to form the polysilicon layer
Implementation Method 7
performing an excimer laser annealing to the amorphous silicon thin film being dehydrogenated to diffuse the dopant ions
Data Source
AI summary
The present disclosure proposes a method of manufacturing a low temperature poly-silicon array substrate, an array substrate and a display panel. The method includes: disposing a substrate, and forming a buffer layer on the substrate; depositing first gas mixture and doped ionized gas by using vapor deposition to form a doped amorphous silicon thin film on the buffer layer; depositing second gas mixture by using vapor deposition to dehydrogenate the amorphous silicon thin film; performing an annealing treatment to the amorphous silicon thin film being dehydrogenated to diffuse dopant ions so as to form a polysilicon layer; and patterning the polysilicon layer.