Plasma Dry Etching of Multi-Metal Compounds Without Blocking Layers
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Solution Overview
Problem
Existing plasma-based dry-etching technologies struggle with compounds containing multiple metals, as each metal reacts at different rates, leading to etching slowdowns or blockages, and the process is complicated by the formation of non-volatile products and deposition.
Innovation Solution
A method and system for dry etching compounds with multiple metals, involving the injection of reactants and a carrier gas, followed by controlled plasma ignition during the decrease of reactant concentration, with precise timing and flow rate adjustments based on individual metal etching rates.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If conventional plasma-based dry-etching is used on multi-metal compounds, then the etching process can proceed, but the etching rate dramatically slows down or stops due to different reaction rates of different metals
Solution Approach 1:
The patent applies periodic action by implementing pulsed plasma ignition cycles where the plasma is ignited for a specific time period during which reactant concentration is decreasing, then stopped. This periodic ignition allows different metals to be etched at controlled rates, preventing the dramatic slowdown that occurs in continuous etching processes. The pulsed nature of the plasma enables recovery periods where slower-reacting metals can be etched without being overwhelmed by faster-reacting metals.
Solution Approach 2:
The patent implements parameter changes by dynamically adjusting the plasma ignition timing and duration based on the decreasing reactant concentration. By controlling the plasma to be present during specific phases of reactant depletion, the process optimizes the etching rate for each metal component. This parameter control ensures that even metals with inherently slow reaction rates can be etched effectively without causing process blockage.
2Productivity
If plasma is continuously ignited to maintain high etching rate, then faster-reacting metals are etched quickly, but slower-reacting metals accumulate on the surface forming blocking layers
Solution Approach 1:
The periodic plasma ignition allows periods of high etching activity followed by pause periods. During the plasma ignition phase, faster-reacting metals are etched at high rates. During the pause phase, the plasma is stopped but reactant concentration continues to decrease, allowing slower-reacting metals to be etched without the competing high-rate etching of faster metals, thereby preventing blocking layer formation.
Solution Approach 2:
The patent maintains continuity of useful action by ensuring that the plasma ignition timing is coordinated with the reactant concentration decrease. The plasma is ignited continuously during the period when reactant concentration is decreasing, ensuring that etching action is always occurring but at optimized rates. This continuous yet controlled action prevents accumulation of unetched material while maintaining overall productivity.
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
Enables independent control over the etching rates of multiple metals, preventing blocking layers and maintaining high etch rates, suitable for advanced semiconductor devices and quantum computing applications.
Implementation Method 1
Plasma-based dry-etching is a critical technology in the semiconductor industry, enabling the precise patterning of materials
Implementation Method 2
Plasmas are rich in electrons, which play a pivotal role in the dissociation of gas molecules into highly reactive radicals
Implementation Method 3
the ionization of some of these molecules. These radicals are far more reactive than their stable molecular counterparts
Implementation Method 4
An additional synergy in plasma-based dry-etching is the energetic ion bombardment of the surface, which breaks material bonds
Implementation Method 5
Dry etching relies on the formation of volatile products through the reaction of neutral molecules from the plasma with the surface atoms of the material being etched
Data Source
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AI summary
A method for dry etching a compound comprising at least two metals involves injecting reactants and a carrier gas into an etching chamber containing the compound, where each metal can be etched by a plasma of at least one reactant. The method includes stopping the injection of one or more reactants to reduce their concentration having a plasma ignited within the chamber during this decrease.