Oxide Semiconductor Layering for Stable Transistor Characteristics
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Solution Overview
Problem
Current semiconductor devices face challenges in achieving consistent transistor characteristics, high reliability, favorable electrical properties, high on-state current, miniaturization, and low power consumption, particularly when using oxide semiconductor materials like CAAC and nc structures.
Innovation Solution
A method for manufacturing a semiconductor device involving a specific layering process with oxide films and conductive films on a substrate, followed by anisotropic etching and heat treatment to form a CAAC-OS structure, which inhibits oxygen diffusion and impurity penetration, enhancing channel formation regions and reducing defects.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If oxide semiconductor materials (CAAC and nc structures) are used to manufacture transistors, then the transistor can achieve high on-state current and low power consumption, but the transistor characteristics show large variations and reliability is insufficient
Solution Approach 1:
The oxide semiconductor film is divided into multiple layers with different crystal structures: a first oxide film with CAAC structure and a second oxide film with nc structure. This segmentation allows each layer to contribute different properties - the CAAC layer provides structural stability while the nc layer enhances carrier mobility, thereby improving transistor characteristic consistency and reliability
Solution Approach 2:
The invention uses a composite oxide semiconductor structure combining CAAC-phase and nc-phase regions within the same film. The CAAC-phase provides oxygen deficiency resistance and structural stability, while the nc-phase provides high carrier mobility. This composite approach resolves the contradiction by achieving both reliability and manufacturing precision through controlled material composition
2Length of moving object
If the oxide film is made thinner to enable device miniaturization, then the device size is reduced, but the electrical characteristics and on-state current deteriorate
Solution Approach 1:
Different regions of the oxide semiconductor film are given different local qualities - the first oxide film region has CAAC structure optimized for oxygen resistance, while the second oxide film region has nc structure optimized for carrier mobility. This local differentiation allows the film to maintain excellent electrical characteristics even at reduced thickness, enabling miniaturization without sacrificing reliability
Solution Approach 2:
Instead of relying solely on film thickness for device performance, the invention introduces a new dimension of control by varying the crystal structure phase composition within the film. This allows thin films to achieve high on-state current and stable electrical characteristics through optimized phase distribution rather than increased thickness
3Manufacturing precision
If conventional manufacturing processes are used for oxide semiconductors, then the process is simpler, but the transistor characteristics show large variations and defects increase
Solution Approach 1:
The invention performs preliminary structuring of the oxide semiconductor film during the deposition process itself, forming the CAAC and nc phase regions in a controlled sequence. This preliminary action establishes the desired crystal structure before subsequent processing, reducing the need for additional annealing or treatment steps and maintaining manufacturing precision without excessive process complexity
Solution Approach 2:
The invention controls specific deposition parameters (temperature, oxygen partial pressure, deposition rate) to induce different crystal phases during film formation. By changing these parameters during the deposition process, the CAAC and nc structures are formed in-situ, achieving high manufacturing precision while avoiding complex post-processing steps
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 approach results in semiconductor devices with reduced variations in transistor characteristics, improved reliability, high on-state current, and low power consumption, enabling miniaturization and high integration while maintaining stable electrical performance.
Implementation Method 1
the oxide semiconductor film has a CAAC-OS structure, so oxygen is not diffused from the oxide semiconductor film to the gate electrode
Implementation Method 2
a CAAC-OS structure, which inhibits oxygen diffusion and impurity penetration
Implementation Method 3
followed by anisotropic etching and heat treatment to form a CAAC-OS structure
Data Source
AI summary
A semiconductor device with less variations in transistor characteristics is provided. A first insulator, first and second oxide films, a first conductive film, a first insulating film, and a second conductive film are deposited and processed to form a first and second oxides, a first conductive layer, a first insulating layer, and a second conductive layer. In the process, a layer is formed to cover the first and second oxides, the first conductive layer, the first insulating layer, and the second conductive layer. The second conductive layer and the layer are removed. A second insulating layer in contact with side surfaces of the first and second oxides, the first conductive layer, and the first insulating layer is formed, and a second insulator is formed thereover. An opening reaching the second oxide is formed in the first conductive layer, the first insulating layer, the second insulating layer, and the second insulator.