Silicon Wafer Gettering Capability Low-Temperature Heat Treatment
Find Innovative SolutionsGenerate Solutions
Solution Overview
Problem
Conventional silicon wafers require long-time high-temperature heat treatment to ensure gettering capability, which is not suitable for low-temperature device processes, necessitating a more reliable evaluation method for semiconductor production.
Innovation Solution
A silicon wafer with a BMD density of 5×10^8/cm^3 to 2.5×10^10/cm^3 and average BMD size of 16 nm to 28 nm in a specific region, heat-treated at 700°C to 1000°C for a time satisfying Y=7.88×10^7×X−22.5, followed by infrared tomography with 50 mW laser power and 50 msec exposure, ensuring gettering capability under low-temperature conditions.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If long-time high-temperature heat treatment is performed to ensure gettering capability, then the gettering capability is improved, but the process time and energy consumption increase
Solution Approach 1:
The invention changes the evaluation parameters by introducing a specific mathematical relationship between heat treatment temperature and time (Y=7.88×10^67×X−22.5), allowing evaluation at lower temperatures with adjusted times. This parameter transformation enables the same gettering capability assessment to be performed under low-temperature conditions, resolving the contradiction between maintaining reliability and reducing process time.
2Reliability
If long-time high-temperature heat treatment is performed to ensure gettering capability, then the gettering capability is improved, but the energy consumption increases
Solution Approach 1:
By transforming the evaluation parameters through the mathematical relationship Y=7.88×10^67×X−22.5, the invention enables gettering capability assessment at lower temperatures. Since energy consumption in heat treatment is directly related to temperature and time, reducing the temperature while adjusting time according to the formula significantly decreases the energy required for evaluation, thus resolving the contradiction between maintaining reliability and reducing energy consumption.
3Reliability
If conventional heat treatment evaluation is used, then the gettering capability can be assessed, but it is not suitable for low-temperature device processes
Solution Approach 1:
The invention transforms the evaluation parameters by establishing a mathematical relationship between temperature and time that enables assessment under low-temperature conditions. This parameter transformation makes the evaluation method adaptable to low-temperature device processes while maintaining the reliability of gettering capability assessment, thus resolving the contradiction between evaluation reliability and process adaptability.
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 reliable evaluation and maintenance of gettering capability in low-temperature device processes without causing dislocations, ensuring the silicon wafer's suitability for semiconductor production.
Implementation Method 1
when the silicon wafer is heat-treated at a temperature X (° C., 700° C.≤X≤1000° C.) for a time Y (min)
Implementation Method 2
subjected to an infrared tomography method in which the laser power is set to 50 mW and the exposure time of a detector is set to 50 msec
Data Source
AI summary
A silicon wafer having a BMD density of 5×108/cm3 or more and 2.5×1010/cm3 or less in a region of 80 μm to 285 μm from the wafer surface when the silicon wafer is heat-treated at a temperature X (° C., 700° C.≤X≤1000° C.) for a time Y (min) and then subjected to an infrared tomography method in which the laser power is set to 50 mW and the exposure time of a detector is set to 50 msec. The time Y and the temperature X satisfy Y=7.88×1067×X−22.5.