Monochromatic Light Source for Semiconductor Film Defect Detection
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Solution Overview
Problem
The semiconductor industry faces challenges in detecting film quality issues of high k1 dielectric materials during manufacturing, as existing methods are either destructive, costly, time-consuming, or not implementable in-line, leading to inefficiencies and waste due to the inability to detect imperfections until after device production.
Innovation Solution
The use of spectroscopic ellipsometry with a monochromatic light source to measure the defect state of dielectric films, allowing for non-destructive, in-line quality evaluation by calculating the imaginary part of the dielectric function and integrating it within the band gap to determine defect states, enabling real-time monitoring and process control.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Measurement precision
If destructive testing methods are used to detect film quality, then defect detection capability is improved, but device integrity is worsened (devices are destroyed in the test process)
Solution Approach 1:
The patent replaces destructive mechanical/electrical testing methods with non-destructive optical measurement methods. Specifically, it uses spectroscopic ellipsometry and photoluminescence imaging to detect film defects without physically damaging the device, thereby maintaining device integrity while achieving defect detection capability.
Solution Approach 2:
The patent introduces optical properties (ellipsometric parameters and photoluminescence intensity) as intermediary indicators to indirectly detect film defects. Instead of directly testing the film in a destructive manner, the optical properties serve as mediators that reveal defect information through non-contact measurement.
2Measurement precision
If quality testing is performed after fabrication completion, then comprehensive defect detection is improved, but manufacturing time is worsened (entire lots need to be scrapped and reworked)
Solution Approach 1:
The patent performs quality testing at intermediate stages during the fabrication process rather than after completion. By measuring film properties in-situ between processing steps, defects are detected early before subsequent fabrication steps are performed, preventing waste of time and resources on defective devices.
Solution Approach 2:
The patent implements continuous quality monitoring by integrating optical measurement capabilities into the fabrication process flow. Testing is performed continuously at multiple stages rather than as a discrete final step, maintaining the productive action while simultaneously detecting defects.
3Productivity
If in-line quality control is implemented, then manufacturing efficiency is improved, but measurement precision requirements are worsened (need for highly sensitive non-destructive measurement)
Solution Approach 1:
The patent changes the measurement parameters from direct electrical/physical film property measurements to optical property measurements (ellipsometric angles, photoluminescence intensity). These optical parameters are highly sensitive to film defects and can be measured non-destructively with high precision, enabling in-line quality control.
Solution Approach 2:
The patent uses optical measurement techniques that can serve multiple functions: they non-destructively characterize film thickness, composition, and defect states simultaneously. This multi-functionality provides the high measurement precision needed for in-line control while maintaining manufacturing efficiency.
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 the early detection of film defects, preventing wasteful processing steps and ensuring repeatable film quality, reducing manufacturing time and costs by enabling in-line quality control and optimizing processing parameters.
Implementation Method 1
measuring the amount of light absorbed by the layer of material at the plurality of energy levels
Implementation Method 2
portions of the light are reflected, absorbed, or passed through the material layer
Implementation Method 3
calculating the imaginary part of the dielectric function and integrating it within the band gap to determine defect states
Data Source
AI summary
Methods and systems for fabricating and testing semiconductor devices are disclosed. In one embodiment, a method of forming a material includes providing a first workpiece, forming a material on the first workpiece using a first process condition, and measuring a defect state of the material using a test that utilizes a monochromatic light source. If the defect state is below a predetermined value, the material is formed on at least one second workpiece using the first process condition.