Polarized Image Acquisition Apparatus for Semiconductor Inspection
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Current pattern inspection apparatuses face challenges in accurately reproducing the pattern image intended for exposure on semiconductor wafers due to differences in optical system configurations between exposure and inspection apparatuses, leading to difficulties in detecting defects and increasing manufacturing time.
Innovation Solution
A polarized image acquisition apparatus and method that utilize a division type half-wave plate and Rochon prism to separate P-polarized and S-polarized waves, allowing for simultaneous imaging and inspection using a common image-forming optical system, enabling the generation of exposure images and pattern inspections with improved precision.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Productivity
If separate optical systems are used for exposure and inspection apparatuses, then each system can be optimized for its specific function, but the manufacturing time increases and complexity increases due to having multiple different systems
Solution Approach 1:
The patent applies universality by designing a common optical system that can perform both exposure and inspection functions. The optical system is configured with adjustable parameters (numerical aperture, illumination conditions, polarization state) that allow it to switch between exposure mode and inspection mode, eliminating the need for separate dedicated systems for each function.
2Productivity
If a common optical system is used for both exposure and inspection, then manufacturing time is reduced and productivity improves, but the precision of pattern inspection may deteriorate due to the need to accommodate both functions
Solution Approach 1:
The patent applies dynamics by making the optical system adjustable and reconfigurable. Key parameters such as numerical aperture, illumination conditions, and polarization state can be dynamically changed between exposure and inspection modes. This allows the system to optimize for inspection precision when needed while maintaining the ability to perform exposure functions.
Solution Approach 2:
The patent applies parameter changes by modifying optical parameters (numerical aperture, illumination wavelength, polarization angle) to switch between exposure and inspection functions. The system can adjust these parameters to match the specific requirements of each mode, ensuring that inspection precision is maintained even when using a common optical system.
3Device complexity
If conventional inspection methods are used without polarization separation, then the optical system is simpler, but the ability to detect certain pattern defects is reduced
Solution Approach 1:
The patent introduces polarization separation optics (wave plates, polarizing beam splitters) as intermediary components in the optical system. These components act as mediators that separate light into different polarization states, enabling the detection of pattern defects that would be invisible with conventional non-polarized inspection methods.
Solution Approach 2:
The patent applies the principle of polarization state changes (analogous to color changes) by using wave plates to alter the polarization state of light. Different polarization states are used to highlight different types of pattern defects, enhancing the inspection capability without significantly increasing system complexity.
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 approach allows for precise acquisition and inspection of polarized images, facilitating the detection of defects and reducing manufacturing time by enabling the use of a common optical system for both exposure and inspection, thus improving yield and efficiency in semiconductor manufacturing.
Implementation Method 1
a division type half-wave plate arranged opposite to the mask substrate with respect to the objective lens, and close to a pupil position of the objective lens, and configured to arrange a P-polarized wave and an S-polarized wave of the transmitted light having passed through the objective lens to be in mutually orthogonal directions
Implementation Method 2
a Rochon prism configured to separate a trajectory of the P-polarized wave from a trajectory of the S-polarized wave
Implementation Method 3
an objective lens configured to receive a transmitted light having passed through the mask substrate
Data Source
AI summary
A polarized image acquisition apparatus includes a division type half-wave plate, located opposite to the mask substrate with respect to an objective lens and near an objective lens pupil position, to arrange P and S polarized waves of the transmitted light having passed through the objective lens to be mutually orthogonal, a Rochon prism to separate trajectories of P and S polarized waves, an imaging lens to form images of P and S polarized waves having passed through the Rochon prism at image formation positions different from each other, a mirror, in a case where one of P and S polarized waves is focused/formed at one of the different image formation positions, to reflect the other wave at the other position, a first sensor to capture an image of one of P and S polarized waves, and a second sensor to capture an image of the other wave.