Dry Etching Method for Display Substrate via Hydrogen Plasma Neutralization
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
In deep via-hole plasma etching for low-temperature polysilicon thin-film transistor arrays, nonuniform plasma distribution leads to charge accumulation, causing microetching and instability in the etching process, which affects the reliability of liquid crystal display panels.
Innovation Solution
A dry etching method involving multiple etching steps with the introduction of plasma, specifically hydrogen plasma, to neutralize electrons accumulated on the side wall of the etching trench, reducing microetching effects by generating plasma between etching steps and maintaining chamber conditions such as pressure and power settings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Manufacturing precision
If deep via-hole plasma etching is performed using conventional methods, then etching depth and speed are achieved, but charge accumulation occurs causing microetching and process instability
Solution Approach 1:
The patent applies periodic action by alternating between etching steps and plasma neutralization steps. After each etching step that may cause charge accumulation, a plasma step is introduced to neutralize charges before the next etching step begins. This periodic intervention prevents microetching and maintains process stability throughout deep via-hole etching.
Solution Approach 2:
The patent converts the harmful effect of plasma (which can cause charge accumulation and microetching) into a beneficial effect by using controlled plasma exposure between etching steps. The plasma, when applied periodically rather than continuously, neutralizes accumulated charges and prevents microetching, transforming a potential harm into a stabilizing mechanism.
2Productivity
If plasma is continuously applied during etching, then etching speed is maintained, but electron accumulation on side walls causes microetching
Solution Approach 1:
The patent implements periodic action by interrupting continuous plasma application with periodic neutralization steps. Instead of continuous plasma exposure that causes electron accumulation, the process alternates between etching phases and plasma neutralization phases, allowing charge dissipation while maintaining overall etching progress.
Solution Approach 2:
The patent applies preliminary action by introducing plasma neutralization steps before charge accumulation becomes problematic. The periodic plasma exposure proactively neutralizes electrons on side walls before they can cause significant microetching, preventing precision degradation rather than correcting it afterward.
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 method effectively reduces microetching, enhancing the stability and reliability of the etching process and the display substrate by neutralizing electrons with hydrogen plasma, preventing physical etching direction changes and maintaining process stability.
Implementation Method 1
Gases have the following two characteristics when existing in the form of plasma: on one hand, chemical activity of the gases in plasma is much higher than that in a normal state
Implementation Method 2
molecules or molecular groups capable of producing ion chemical reaction with a thin film are generated using glow discharge of a particular gas
Implementation Method 3
the plasma can also be guided and accelerated by an electric field so that the plasma has certain energy
Implementation Method 4
when the plasma bombards the surface of an object being etched, the plasma can hit out atoms of the materials of the etched object. In this way, the objective of etching can be achieved by physical energy transfer
Implementation Method 5
adding plasma into an etch chamber between any two successive etching steps, wherein the plasma neutralizes electrons accumulated on a side wall of an etching trench
Data Source
AI summary
A dry etching method includes performing at least two etching steps, and further includes injecting protective gas into an etch chamber for processing between any two successive etching steps, wherein the protective gas generates plasma to neutralize electrons accumulated on a side wall of an etching trench. According to the present disclosure, hydrogen plasma is added in an etching process to remove the electrons accumulated on the side wall of the etching trench so as to reduce the microetching effect in multiple etching. In this way, process stability and reliability of a display substrate are improved.