Which Tests Require Attention to Carrier Lifetime Values (Part 3 of 10)

1. Semiconductor Device Manufacturing (Highly Relevant)

High-Temperature Diffusion/Annealing Processes:
Quartz tubes are commonly used in semiconductor wafer high-temperature diffusion furnaces for doping (such as phosphorus or boron diffusion) or annealing (activating dopants).
Carrier lifetime is a key parameter for evaluating silicon wafer quality. If quartz tube impurities (such as metal ions) contaminate the wafers, it can lead to increased carrier recombination and reduced lifetime.
Tests involve measuring the minority carrier lifetime to evaluate the process impact on the wafer’s electrical performance.

Epitaxy:
Quartz tubes are used in CVD (Chemical Vapor Deposition) reaction chambers. If the tube wall becomes contaminated or experiences devitrification, the quality of the epitaxial layer may be affected, resulting in reduced carrier lifetime.

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2. Photovoltaic (Solar Cell) Testing

Solar Silicon Wafer Processing:
In high-efficiency solar cell processes such as PERC and TOPCon, quartz tubes are used for passivation layer deposition (such as SiNx or Al₂O₃) or high-temperature firing.
Carrier lifetime directly affects the cell’s conversion efficiency. If the quartz tube introduces contamination, the surface recombination rate of the wafer will increase.
Measurements are carried out using QSSPC (Quasi-Steady-State Photoconductance) or μ-PCD (Microwave Photoconductance Decay) to determine minority carrier lifetime.

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3. Materials Research (e.g., Wide-Bandgap Semiconductors)

SiC/GaN Device Processes:
High-temperature processes (>1500°C) for silicon carbide (SiC) or gallium nitride (GaN) devices require ultra-pure quartz tubes. Impurities can increase interface state density, leading to decreased carrier lifetime.
Research often focuses on the electrical properties of epitaxial layers or oxide layers.

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4. Other Related Tests

Photodetector or Sensor Manufacturing:
Carrier lifetime affects response speed. If quartz tubes contaminate sensitive materials (such as InGaAs), device performance can deteriorate.

Laboratory-Level Testing:
Some customers may simply use quartz tubes as reaction vessels to test the carrier dynamics of new materials (such as perovskites).

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Test Relevance

Carrier Lifetime Sensitivity:
This parameter is critical in semiconductor and photovoltaic fields, while typical industrial or chemical experiments generally do not measure it specifically.

High-Temperature Applications of Quartz Tubes:
General chemical experiments have relatively low purity requirements for quartz tubes, whereas semiconductor/photovoltaic processes are extremely sensitive to contamination.