Grid Potential Control for Atomic Layer Dry Etching Precision
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Solution Overview
Problem
Conventional atomic layer etching methods face challenges in precise ion energy control, leading to radical loss and contamination, as well as charge accumulation on insulator materials during etching, which prolongs process time and affects etching selectivity.
Innovation Solution
A dry etching method using a grid system with sequential grids and a substrate support structure, where potential control allows for radical adsorption without a shutter and charge neutralization during desorption, enabling efficient etching by selectively applying potentials to the grids and substrate.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Loss of substance
If a shutter is used to block ions and electrons during radical adsorption, then radical loss is reduced, but process time is lengthened and shutter contamination occurs
Solution Approach 1:
The shutter component is completely removed from the system. Instead of using a mechanical shutter to block ions and electrons, the patent applies electric field control through grid potential adjustment to selectively allow only radicals to reach the substrate during the adsorption step, eliminating both radical loss and process time extension caused by shutter operation
Solution Approach 2:
The mechanical shutter system is replaced with an electric field control system. By adjusting the potential of the grid relative to the plasma potential, the system electrically filters ions and electrons while allowing neutral radicals to pass through, achieving the same protective function without mechanical moving parts
2Loss of substance
If a shutter is used to block ions and electrons during radical adsorption, then radical loss is reduced, but shutter contamination occurs
Solution Approach 1:
The shutter component is completely removed from the system. Instead of using a mechanical shutter to block ions and electrons, the patent applies electric field control through grid potential adjustment to selectively allow only radicals to reach the substrate during the adsorption step, eliminating both radical loss and process time extension caused by shutter operation
Solution Approach 2:
The mechanical shutter system is replaced with an electric field control system. By adjusting the potential of the grid relative to the plasma potential, the system electrically filters ions and electrons while allowing neutral radicals to pass through, achieving the same protective function without mechanical moving parts that can be contaminated
3Manufacturing precision
If ion-beam etching is performed on insulator material, then etching is achieved, but charge accumulation occurs on the substrate
Solution Approach 1:
The etching process is divided into periodic cycles with distinct phases: an adsorption step where radicals are introduced to modify the surface, followed by a desorption step where ion-beam etching removes the modified layer. This periodic alternation allows charge to be managed between cycles, preventing accumulation while maintaining etching precision
Solution Approach 2:
The grid potential is dynamically adjusted between different values during the process. During radical adsorption, the grid potential is set to attract radicals while repelling ions. During ion-beam etching, the potential is changed to enable ion extraction while managing charge buildup on the insulator substrate through controlled potential differences
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
This method reduces radical loss, eliminates shutter contamination, and improves etching selectivity by controlling charge accumulation, thereby shortening process time and enhancing etching precision.
Implementation Method 1
first radicals contained in first plasma generated from the plasma generator
Implementation Method 2
plasma generated from the plasma generator
Implementation Method 3
irradiating ion-beams extracted from second plasma generated from the plasma generator onto the surface
Implementation Method 4
potential control of a grid and substrate supporting an etching target thereon
Implementation Method 5
adsorbing first radicals into a surface of the etching target
Implementation Method 6
irradiating ion-beams extracted from second plasma generated from the plasma generator onto the surface of the etching target into which the radicals have been adsorbed, thereby desorbing a surface atomic layer
Implementation Method 7
irradiating electrons generated from the second plasma to the surface of the etching target, thereby neutralizing the surface
Data Source
AI summary
A dry etching method includes a first step of adsorbing first radicals into a surface of an etching target, wherein the first radicals are contained in first plasma generated from a plasma generator; and a second step of irradiating ion-beams extracted from second plasma generated from the plasma generator onto the surface of the etching target into which the radicals have been adsorbed, thereby desorbing a surface atomic layer of the etching target, wherein the first step is performed such that: a positive potential greater than a potential of the first plasma is applied to one or two selected from first to third grids, while a ground potential is applied to the rest thereof; and a negative potential equal to or lower than a potential of the third grid is applied to a substrate support structure.