MoSiON Phase Shift Film for ArF Lithography EB Defect Repair
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Solution Overview
Problem
Conventional phase shift masks used in photolithography with ArF excimer laser light face challenges in achieving high transmittance while maintaining a predetermined phase difference, leading to difficulties in detecting the etching end point during EB defect repair and resulting in inaccurate defect repair and potential substrate damage.
Innovation Solution
A mask blank with a phase shift film made of metal silicide oxynitride, specifically molybdenum silicon oxynitride (MoSiON), is developed, featuring a transmittance of 10% to 20% and a phase difference of 150 to 190 degrees, with a metal content ratio of 5% to 10% and oxygen content of 10% or more, facilitating accurate EB defect repair by enhancing etching end point detection.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Illumination intensity
If a phase shift film with high transmittance (10% or more) is used, then the transmittance of exposure light is improved, but the detection precision of etching end point during EB defect repair deteriorates
Solution Approach 1:
The invention changes the chemical composition parameters of the phase shift film by introducing oxygen into the MoSiN material system, creating MoSiON with specific oxygen content (10-40 atom%). This compositional parameter change simultaneously achieves high transmittance (10% or more) and maintains good etching end point detection capability during EB defect repair, resolving the contradiction between these two requirements.
Solution Approach 2:
The invention uses a composite material MoSiON (molybdenum silicide oxynitride) that combines metal (molybdenum), silicon, nitrogen, and oxygen in specific proportions. This composite material structure enables the phase shift film to achieve both high transmittance and adequate etching end point detection, overcoming the limitations of conventional single-material systems.
2Reliability
If a phase shift film with high transmittance is used, then the phase shift effect is improved, but the accuracy of EB defect repair deteriorates due to inaccurate etching end point detection
Solution Approach 1:
By adjusting the oxygen content parameter in the MoSiON phase shift film to 10-40 atom%, the invention achieves a balance where the phase shift effect (150-190 degrees) is maintained or improved while the etching end point detection during EB defect repair remains accurate, thereby ensuring both reliability and manufacturing precision.
Solution Approach 2:
The invention optimizes the local chemical composition of the phase shift film by controlling the distribution and content of oxygen atoms within the MoSiN matrix, creating a material with tailored local properties that simultaneously provide high transmittance for phase shift and adequate signal contrast for etching end point detection.
3Quantity of substance
If a phase shift film with transmittance of 10% or more is used, then the light transmission is improved, but the etching end point detection during EB defect repair becomes difficult
Solution Approach 1:
The invention modifies the material composition parameters by incorporating oxygen (10-40 atom%) into MoSiN to form MoSiON, which achieves transmittance of 10% or more while maintaining sufficient etching end point detection capability during EB defect repair, thus reducing detection difficulty.
Solution Approach 2:
The oxygen component in MoSiON acts as an intermediary element that mediates between the conflicting requirements of high light transmission and good etching end point detection. The specific oxygen content range (10-40 atom%) optimizes the balance between these two functions.
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 solution enables high-transmittance phase shift masks with fewer black defects, allowing for precise EB defect repair and preventing substrate damage, thus improving the accuracy and yield of semiconductor device manufacturing.
Implementation Method 1
a function to generate a phase difference of not less than 150 degrees and not more than 190 degrees between the exposure light transmitted through the phase shift film and the exposure light transmitted through the air
Implementation Method 2
a xenon difluoride (XeF2) gas is supplied to a black defect portion of a light shielding film while irradiating the portion with electron beams to etch and remove the black defect portion
Implementation Method 3
irradiating the portion with electron beams to etch and remove the black defect portion
Data Source
AI summary
A mask blank including a phase shift film is provided, wherein the phase shift film has a transmittance with respect to exposure light of an ArF excimer laser of not less than 10% and not more than 20% and is configured to transmit the exposure light to have a phase difference of not less than 150 degrees and not more than 190 degrees with respect to exposure light transmitted through the air for the same distance as a thickness of the phase shift film. A ratio of the metal content to the total content of the metal and silicon in the phase shift film is not less than 5% and not more than 10%, the oxygen content in the phase shift film is 10 atom % or more, and the silicon content in the phase shift film is three times or more the oxygen content.