Composite Oxide Semiconductor Layout to Suppress Spinel Formation
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The formation of a spinel crystal structure in In--Ga--Zn-based oxide semiconductors can adversely affect the electrical characteristics and reliability of semiconductor devices, such as transistors.
Innovation Solution
A composite oxide semiconductor is developed, comprising a first region with an atomic ratio of In:M:Zn = 4:2:3 and a plurality of second regions with an atomic ratio of In:M:Zn = 2:0:3, where the second regions have a higher concentration of indium and higher conductivity than the first region, and are three-dimensionally surrounded by the first region.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If the composition is adjusted to achieve higher indium concentration for improved conductivity, then the electrical characteristics improve, but the spinel crystal structure is more likely to form which adversely affects reliability
Solution Approach 1:
The patent applies local quality by creating a composite oxide semiconductor with spatially varying composition: a first region with lower indium concentration (In:M:Zn = 4:2:3) and second regions with higher indium concentration (In:M:Zn = 2:0:3). This allows high-indium regions to provide high conductivity while low-indium regions suppress spinel crystal formation, resolving the contradiction between electrical performance and structural stability.
Solution Approach 2:
The patent uses composite materials by combining two distinct oxide semiconductor regions with different compositions. The first region (In-Ga-Zn oxide) and second regions (In-Zn oxide) form a composite structure where each region contributes different properties: the first region suppresses spinel formation while the second regions provide high conductivity through higher indium concentration.
2Reliability
If indium concentration is increased to improve carrier mobility, then electrical conductivity improves, but the structural stability deteriorates due to spinel phase formation
Solution Approach 1:
The patent implements local quality by distributing high-indium second regions within a low-indium first region matrix. The high-indium second regions (In:M:Zn = 2:0:3) provide high carrier mobility and conductivity, while the surrounding low-indium first region (In:M:Zn = 4:2:3) maintains structural stability and prevents spinel phase formation, thus resolving the contradiction between carrier mobility and structural stability.
Solution Approach 2:
The patent applies parameter changes by varying the indium concentration parameter across different regions. The first region has indium concentration corresponding to ratio 4:2:3, while the second regions have higher indium concentration at ratio 2:0:3. This parameter variation allows optimization of both structural stability (lower In) and carrier mobility (higher In) in different spatial locations.
Data Source
AI summary
A novel material is provided. A composite oxide semiconductor in which a first region and a plurality of second regions are mixed is provided. Note that the first region contains at least indium, an element M (the element M is one or more of Al, Ga, Y, and Sn), and zinc, and the plurality of second regions contain indium and zinc. Since the plurality of second regions have a higher concentration of indium than the first region, the plurality of second regions have a higher conductivity than the first region. An end portion of one of the plurality of second regions overlaps with an end portion of another one of the plurality of second regions. The plurality of second regions are three-dimensionally surrounded with the first region.