HF Substrate Cleaning via Adsorption-Desorption Pressure Cycling
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Existing substrate processing methods are ineffective in efficiently removing etching residues and particles from semiconductor substrates, particularly due to limitations in controlling temperature and pressure conditions to desorb hydrogen fluoride effectively.
Innovation Solution
A substrate processing method involving the controlled supply of hydrogen fluoride gas and temperature/pressure adjustments within specific regions above and below the adsorption equilibrium pressure curve of hydrogen fluoride, allowing for the desorption of etching residues and particles from the substrate surface.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If hydrogen fluoride gas is supplied at high pressure to remove etching residues, then cleaning effectiveness is improved, but hydrogen fluoride adsorption on substrate increases causing over-etching
Solution Approach 1:
The patent applies parameter changes by dynamically adjusting both temperature and pressure of hydrogen fluoride gas during the cleaning process. The system transitions from high pressure (for effective residue removal) to low pressure (to prevent over-etching), while simultaneously adjusting temperature to control hydrogen fluoride adsorption and desorption, thereby resolving the contradiction between cleaning effectiveness and etching control.
Solution Approach 2:
The patent implements periodic action through multi-stage pressure and temperature cycling. The process alternates between high-pressure/low-temperature phases (for residue removal) and low-pressure/high-temperature phases (for desorption and prevention of over-etching), creating a rhythmic pattern that achieves thorough cleaning while maintaining precision.
2Loss of substance
If temperature is increased to desorb hydrogen fluoride from substrate, then hydrogen fluoride removal is improved, but etching residues may re-adsorb
Solution Approach 1:
The patent uses periodic action by alternating temperature and pressure conditions in specific sequences. High temperature is applied temporarily to desorb hydrogen fluoride, followed immediately by low pressure conditions that prevent residue re-adsorption. This rhythmic cycling ensures hydrogen fluoride removal while maintaining substrate cleanliness.
Solution Approach 2:
The patent applies parameter changes by coordinating temperature and pressure adjustments together. When temperature is increased for desorption, pressure is simultaneously decreased to shift the equilibrium away from adsorption, preventing etching residues from re-adsorbing onto the substrate surface.
3Productivity
If pressure is maintained high to keep hydrogen fluoride on substrate for cleaning, then cleaning efficiency is improved, but hydrogen fluoride cannot be effectively desorbed
Solution Approach 1:
The patent implements periodic action through cyclic pressure changes. The system operates in high-pressure modes for extended cleaning periods, then transitions to low-pressure modes for desorption periods. This rhythmic pattern maintains cleaning efficiency while periodically enabling effective hydrogen fluoride desorption from the substrate.
Solution Approach 2:
The patent applies parameter changes by dynamically switching between high and low pressure conditions. During high-pressure phases, cleaning efficiency is maximized; during low-pressure phases, hydrogen fluoride desorption is enabled. The coordinated parameter changes ensure both cleaning effectiveness and desorption capability are achieved throughout the process.
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 enables the effective removal of etching residues and particles by leveraging the adsorption and desorption properties of hydrogen fluoride, improving substrate cleaning efficiency and precision.
Implementation Method 1
controlling a temperature of the substrate support to a first temperature, and a pressure of the hydrogen fluoride gas in the chamber to a first pressure; and controlling the temperature of the substrate support to a second temperature, and the pressure of the hydrogen fluoride gas in the chamber to a second pressure. In a graph with a horizontal axis indicating a temperature and a vertical axis indicating a pressure, the first temperature and the first pressure are positioned in a first region above an adsorption equilibrium pressure curve of hydrogen fluoride
Implementation Method 2
the second temperature and the second pressure are positioned in a second region below the adsorption equilibrium pressure curve
Data Source
AI summary
A substrate processing method includes: (a) disposing a substrate on a substrate support provided in a chamber of a substrate processing apparatus; (b) supplying a processing gas including hydrogen fluoride gas into the chamber; (c) controlling a temperature of the substrate support to a first temperature, and a pressure of the hydrogen fluoride gas in the chamber to a first pressure; and (d) controlling the temperature of the substrate support to a second temperature, and the pressure of the hydrogen fluoride gas in the chamber to a second pressure. In a graph with a horizontal axis indicating a temperature and a vertical axis indicating a pressure, the first temperature and the first pressure are positioned in a first region above an adsorption equilibrium pressure curve of hydrogen fluoride, and the second temperature and the second pressure are positioned in a second region below the adsorption equilibrium pressure curve.