Indium Multi-Metal CVD Source Material for Stable Film Formation
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Solution Overview
Problem
Existing chemical vapor deposition source materials for indium-based films are unstable and require complex handling, leading to residue formation and complications in film formation processes, especially for composite oxide films like IGZO.
Innovation Solution
A chemical vapor deposition source material comprising specific indium and other metal compounds, represented by general formulae (1) to (6), stabilized by coexistence with compounds like gallium or zinc, allowing for long-term stability and simplified handling.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If indium compounds with alkylcyclopentadienyl ligands are used as CVD source materials, then high-throughput film formation is achieved, but thermal stability is insufficient and residues are formed
Solution Approach 1:
The patent changes the chemical parameters of the source material by replacing simple alkyl groups with bulky, branched alkyl groups (such as tert-butyl groups) on the cyclopentadienyl ligands. This structural modification increases thermal stability and prevents decomposition reactions that produce residues, while maintaining the volatility needed for high-throughput CVD processes.
Solution Approach 2:
The patent uses composite source materials containing mixed ligand systems on the cyclopentadienyl ring, combining electron-donating and electron-withdrawing groups to optimize both thermal stability and reactivity. This composite ligand structure prevents disproportionation reactions while maintaining adequate vapor pressure for efficient film deposition.
2Ease of operation
If liquid source materials are used for CVD, then easy handling and feeding are achieved, but long-term stability at room temperature is insufficient
Solution Approach 1:
The patent modifies the physical and chemical parameters of the source material by incorporating bulky branched alkyl groups that increase molecular sterics and reduce intermolecular interactions. This changes the material from unstable liquid at room temperature to stable liquid or low-melting solid that can be stored long-term without decomposition, while maintaining ease of handling through appropriate viscosity and melting point control.
3Manufacturing precision
If multiple metal source materials are added individually to form composite oxide films, then film composition control is achieved, but process complexity increases
Solution Approach 1:
The patent combines multiple metal sources into a single molecular complex or mixed-ligand compound where different metals are coordinated to the cyclopentadienyl system. This merging approach allows simultaneous introduction of multiple elements (such as In, Ga, Zn) in controlled ratios through a single source material, simplifying the deposition process while maintaining precise compositional control.
Solution Approach 2:
The patent develops universal source materials based on cyclopentadienyl metal complexes that can serve multiple functions: providing the metal source, controlling stoichiometry through ligand design, and enabling co-deposition of multiple elements. This multi-functional approach replaces the need for separate handling of multiple individual metal sources.
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 source material maintains stability for several days to months at room temperature, facilitating the formation of composite oxide films with controlled composition and quality, simplifying the film formation process.
Implementation Method 1
chemical vapor deposition (CVD)... formation of a film containing indium and one or more of the other metals by chemical vapor deposition
Data Source
AI summary
Provided are a CVD source material used in production of a film containing indium and one or more of the other metals, which is stably preservable over the long term and easily handled, and a production method thereof. The CVD source material comprises ≥0.1 mol of one or more compounds of formulae (3) to (6) on the 100 mol basis of a compound of formula (1) or (2). In(C5H4R) . . . (1), In(C5(CH3)4R) . . . (2), M1(C5H4R) . . . (3), M2 (C5H4R)n . . . (4), M1(C5(CH3)4R) . . . (5), and M2(C5(CH3)4R)n . . . (6). In formulae (1) to (6), each R is independently hydrogen or an alkyl group having 1 to 6 carbons, in formulae (3) and (5), M1 is a metal excluding indium, in formulae (4) and (6), M2 is a metal excluding indium and n is an integer of 2 to 4.