Charged Particle Beam Focus Control via Ozone Partial Pressure
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
The challenge in charged particle beam writing apparatuses is that the focus of the electron beam deviates when cleaning gas is flowed, leading to beam drift and contamination issues, which existing methods fail to adequately address.
Innovation Solution
A charged particle beam writing apparatus that includes a measurement unit to control the partial pressure of a gas within the chamber, allowing for focus adjustment using a deflector to maintain beam focus and inhibit beam drift by removing contaminants with ozone gas, generating oxygen radicals to dissolve hydrocarbon contaminants.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If cleaning gas is flowed to remove contaminants, then beam drift is inhibited, but focus deviation occurs
Solution Approach 1:
The patent changes the physical parameters of the gas environment by controlling partial pressure of cleaning gas (ozone) in the chamber. By adjusting the concentration of ozone gas, the system maintains beam stability while compensating for focus deviation caused by gas flow, thus resolving the contradiction between reliability and manufacturing precision
Solution Approach 2:
The patent implements a feedback mechanism where the focus position is continuously monitored and adjusted based on the presence of cleaning gas. The system detects focus deviation caused by ozone gas flow and automatically corrects it by adjusting the objective lens, thereby maintaining both beam stability and focus accuracy
2Object-generated harmful factors
If cleaning gas is flowed to remove contaminants, then deflector contamination is reduced, but focus position shifts
Solution Approach 1:
The patent introduces ozone gas as an intermediary substance that mediates between the beam path and contaminants. The ozone gas acts as a cleaning agent that removes contaminants from the deflector without directly interfering with the beam, while the focus adjustment mechanism compensates for any position shifts caused by the gas presence
Solution Approach 2:
The patent utilizes ozone, a strong oxidant, to accelerate the removal of organic contaminants from the deflector surface. The oxidative action of ozone effectively breaks down and removes contaminants, reducing beam drift while the focus adjustment system compensates for the resulting focus position shifts
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 solution effectively corrects focus deviations and reduces beam drift by maintaining a controlled gas environment, ensuring precise pattern writing on semiconductor devices by adjusting the focus position based on the partial pressure of the cleaning gas, thereby improving the accuracy and reliability of the electron beam writing process.
Implementation Method 1
a measurement unit configured to measure a partial pressure of a predetermined gas in the chamber
Implementation Method 2
an objective lens configured to focus the charged particle beam on a surface of the target object
Implementation Method 3
removing contaminants with ozone gas, generating oxygen radicals to dissolve hydrocarbon contaminants
Data Source
AI summary
A charged particle beam writing apparatus includes an emission unit to emit a charged particle beam, a stage to mount thereon a target object to be written, an objective lens to focus the charged particle beam on a surface of the target object, a chamber to house the stage, a measurement unit to measure a partial pressure of a predetermined gas in the chamber in a state where a pressure inside the chamber is controlled to be lower than an atmospheric pressure, and an adjustment unit to adjust a focus position for focusing the charged particle beam on the target object, based on the partial pressure of the predetermined gas.