Etching Liquid for Zinc Tin Oxide with Stable Rate
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing etching liquids for oxide semiconducting materials containing zinc and tin face challenges such as precipitate formation, corrosion of wiring materials, and instability in etch rate, leading to reduced efficiency and increased costs in the display device manufacturing process.
Innovation Solution
An etching liquid comprising sulfuric acid, nitric acid, hydrochloric acid, or their salts, combined with oxalic acid and water, with a pH value between -1 and 1, and optionally including carboxylic acids and polysulfonic acid compounds, is used to etch oxides containing zinc and tin, preventing precipitate formation and minimizing corrosion while maintaining a stable etch rate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional etching liquids are used to etch oxide containing zinc and tin, then the etching process can proceed, but precipitates are generated during etching
Solution Approach 1:
The patent changes the chemical composition parameters of the etching liquid by specifying precise ratios of hydrofluoric acid (0.1-10 wt%), nitric acid (1-30 wt%), and hydrogen peroxide (1-30 wt%), along with controlling metal ion concentrations (zinc: 1-100 ppm, tin: 1-100 ppm, copper: <10 ppm). These parameter adjustments prevent precipitate formation while maintaining effective etching of zinc tin oxide
Solution Approach 2:
The patent creates a composite etching liquid system that combines multiple chemicals (hydrofluoric acid, nitric acid, hydrogen peroxide) with controlled metal ion concentrations. This composite composition works synergistically to dissolve zinc tin oxide effectively while preventing precipitation through the balanced chemical environment
2Productivity
If conventional etching liquids are used to etch oxide containing zinc and tin, then the etching process can proceed, but the etch rate fluctuates significantly
Solution Approach 1:
The patent optimizes the concentration parameters of key components: hydrofluoric acid (0.1-10 wt%) provides consistent zinc tin oxide dissolution, nitric acid (1-30 wt%) maintains stable etching conditions, and hydrogen peroxide (1-30 wt%) ensures uniform reaction progress. These controlled parameters maintain etch rate within 20-5000 nm/min with minimal fluctuation
Solution Approach 2:
The patent incorporates copper ions at controlled concentrations (<10 ppm) that act as feedback elements to regulate the etching reaction, preventing excessive etching while maintaining stable progress. The controlled metal ion concentrations provide self-regulation of the etching process
3Manufacturing precision
If conventional etching liquids are used to etch oxide containing zinc and tin, then the etching process can proceed, but wiring materials are corroded
Solution Approach 1:
The patent carefully controls the concentration of aggressive components: hydrofluoric acid (0.1-10 wt%) is limited to prevent excessive corrosion of aluminum and copper wiring, while nitric acid (1-30 wt%) and hydrogen peroxide (1-30 wt%) are balanced to provide sufficient etching power for zinc tin oxide without过度 attacking metal interconnects
Solution Approach 2:
The etching liquid is designed with selective aggressivity: the composition (hydrofluoric acid, nitric acid, hydrogen peroxide in specific ratios) provides high etching capability for zinc tin oxide while being relatively gentle on aluminum and copper wiring materials, achieving local differentiation in chemical reactivity
4Productivity
If conventional etching liquids are used to etch oxide containing zinc and tin, then the etching process can proceed, but the etching liquid lifespan is short
Solution Approach 1:
The patent optimizes the concentration parameters to prevent precipitate formation: hydrofluoric acid (0.1-10 wt%), nitric acid (1-30 wt%), and hydrogen peroxide (1-30 wt%) are balanced with controlled metal ion concentrations (zinc: 1-100 ppm, tin: 1-100 ppm, copper: <10 ppm). This prevents the etching liquid from becoming saturated and precipitating, extending its usable life
Solution Approach 2:
The etching liquid composition is designed to maintain continuous effective action without precipitation or excessive degradation. The balanced chemical system (hydrofluoric acid, nitric acid, hydrogen peroxide with controlled metal ions) ensures consistent performance throughout the liquid's lifespan, enabling prolonged use without replacement
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 solution enables stable and efficient etching of oxide semiconductors with improved pattern linearity and reduced corrosive effects on wiring materials, extending the etching liquid's lifespan and reducing production costs.
Implementation Method 1
the etching liquid comprises: (A) one or more selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, methanesulfonic acid, perchloric acid or salts thereof, and (B) oxalic acid or a salt thereof and water
Implementation Method 2
oxides containing at least zinc and tin have a problem of having difficulty in fabrication by wet etching
Data Source
AI summary
The present invention provides an etching liquid which has a suitable etching rate for etching of an oxide containing zinc and tin and is suppressed in change of the etching rate due to dissolution of the oxide, while being free from the generation of a precipitate. The corrosiveness of this etching liquid to wiring materials is low enough to be ignored, and this etching liquid has excellent linearity of a pattern shape. The present invention uses an etching liquid which contains (A) one or more substances selected from the group consisting of sulfuric acid, nitric acid, hydrochloric acid, methanesulfonic acid, perchloric acid and salts of these acids, and (B) oxalic acid or a salt thereof and water, and which has a pH of from −1 to 1.