Vaporized Solvent Dry Strip for Semiconductor Photoresist Removal
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Solution Overview
Problem
Current dry strip processes for post-implantation photoresist and post-etch residue removal in semiconductor manufacturing cause silicon or silicon-germanium loss and damage to low-k films, with hydrogen-based processes having low resist removal rates and introducing device shifts.
Innovation Solution
A non-oxidizing dry-strip process using vaporized solvents injected into a process chamber, combined with plasma generation to expose the workpiece to solvent radicals for effective photoresist and residue removal with reduced surface damage and oxidation.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If oxygen-containing plasma dry strip is used for photoresist removal, then photoresist removal effectiveness is improved, but silicon or silicon-germanium loss occurs and low-k films are damaged
Solution Approach 1:
The patent changes the chemical composition parameters of the plasma by introducing fluorocarbon-based compounds (CF4, C2F6, C3F8) and aromatic hydrocarbons (toluene, xylene) to replace traditional oxygen-containing plasma. This parameter change modifies the chemistry from oxidizing to a mixed chemistry that provides both etching power and protective carbon deposition, resolving the contradiction between removal effectiveness and substrate damage
Solution Approach 2:
The patent employs a composite chemical approach by combining fluorocarbon-based plasma (providing F radicals for photoresist etching) with aromatic hydrocarbon additives (providing carbon for protective polymer deposition). This composite chemistry simultaneously achieves effective photoresist removal while depositing a protective carbon layer that prevents silicon loss and low-k film damage
2Object-affected harmful factors
If hydrogen-based processes are used for photoresist removal, then substrate loss is reduced, but resist removal rate decreases and device shifts occur due to vacancy formation
Solution Approach 1:
The patent changes the chemical parameters by replacing hydrogen-based plasma with fluorocarbon-based plasma enhanced by aromatic hydrocarbons. This parameter change increases the etching power through F radical chemistry while the aromatic additives provide carbon deposition that protects the substrate, thereby increasing resist removal rate without sacrificing substrate protection
Solution Approach 2:
The aromatic hydrocarbon compounds act as intermediary substances that mediate between the fluorocarbon plasma and the substrate. They provide carbon radicals that deposit as a protective polymer layer on the substrate surface, preventing direct damage from the reactive fluorocarbon species while allowing effective photoresist removal to proceed
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 process achieves effective removal of photoresist and residue with minimized surface damage and oxidation, addressing the limitations of existing methods by using solvent vapor and plasma to clean semiconductor workpieces.
Implementation Method 1
vaporizing a solvent to create a vaporized solvent
Implementation Method 2
combined with plasma generation to expose the workpiece to solvent radicals
Data Source
AI summary
Processes and apparatuses for the treatment of semiconductor workpieces are provided. In some embodiments, a method can include placing the workpiece into a process chamber; vaporizing a solvent to create a vaporized solvent; introducing the vaporized solvent into the process chamber; and exposing the workpiece to the vaporized solvent.