Low-Temperature Crystallization of InGaZn Oxide Semiconductor Layers
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Solution Overview
Problem
Conventional methods for crystallizing oxide semiconductor layers require high temperatures of 500°C or more, which limits the use of flexible substrates and makes it difficult to manufacture large-area display devices with stable support substrates.
Innovation Solution
A method for crystallizing an oxide semiconductor layer by depositing In—Ga—Zn oxide on a substrate heated to 200-300°C, followed by heat treatment to form a crystallized layer throughout its thickness, using a target with an In—Ga—Zn composition of 1:1:1.10–1.25 to compensate for Zn loss during deposition and heat treatment.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If high temperature heat treatment (500°C or more) is used for crystallization, then crystallization characteristics are improved, but substrate stability deteriorates and flexible substrate usage becomes impossible
Solution Approach 1:
The patent changes the temperature parameter from conventional high temperature (500°C or more) to low temperature (200-300°C) range, enabling crystallization while maintaining substrate stability and allowing flexible substrate usage
Solution Approach 2:
The patent uses a composite target material comprising In-Ga-Zn oxide with specific composition ratios (In:Ga:Zn = 1:1:(1.10-1.25)) to achieve crystallization at low temperatures, combining multiple elements to obtain desired crystallization characteristics without high temperature treatment
2Manufacturing precision
If high temperature heat treatment (500°C or more) is used for crystallization, then crystallization characteristics are improved, but manufacturing complexity increases due to substrate selection limitations
Solution Approach 1:
By changing the temperature parameter to low temperature range (200-300°C), the patent removes the constraint on substrate selection, allowing use of flexible substrates and simplifying the manufacturing process for large-area display devices
3Stability of the object's composition
If Zn content in target is increased to compensate for Zn loss, then composition control is improved, but deposition process complexity increases
Solution Approach 1:
The patent optimizes the Zn content parameter in the target material to a specific range (In:Ga:Zn = 1:1:(1.10-1.25)), which compensates for Zn loss during deposition and heat treatment while maintaining a relatively simple deposition process
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 achieves enhanced crystallization characteristics and reliability of the semiconductor device, allowing for stable operation under bias stress and enabling the use of flexible substrates without temperature-related limitations.
Implementation Method 1
depositing an In—Ga—Zn oxide over a substrate while heating the substrate to a temperature of 200 to 300° C.
Implementation Method 2
heat-treating the deposited In—Ga—Zn oxide, thereby forming an oxide semiconductor layer crystallized throughout an entire thickness of the oxide semiconductor layer
Implementation Method 3
heat-treating the deposited In—Ga—Zn oxide, thereby forming an oxide semiconductor layer crystallized throughout an entire thickness of the oxide semiconductor layer
Implementation Method 4
depositing an In—Ga—Zn oxide over a substrate
Data Source
AI summary
A display device includes a gate electrode on a substrate of a semiconductor device, a gate insulating film over the gate electrode, an active layer comprising an oxide including indium, zinc and gallium on the gate insulating film, and overlapping the gate electrode, and a source electrode and a drain electrode that are spaced apart from each other, wherein the active layer is formed from a zinc-rich target material, and an atomic % ratio of indium, zinc and gallium in the active layer is different from an atomic % ratio of the zinc-rich target material.