基于等倾干涉的SiC外延层测厚研究
Research on Thickness Measurement of SiC Epitaxial Layer Based on Equal-Inclination Interference
薛紫涵 1刘婧1
作者信息
- 1. 辽宁工程技术大学电子与信息工程学院，葫芦岛市，125105
- 折叠
摘要
针对碳化硅（SiC）外延层厚度精准测量需求，本文基于红外反射光谱法与等倾干涉理论，构建适配双光束与多光束场景的厚度计算模型，解决传统测量中干涉条纹干扰、折射率非恒定等关键问题。首先，建立双光束干涉模型，结合光程差与相位差推导厚度计算公式；其次，引入三阶柯西色散模型描述折射率-波长关系，通过非线性最小二乘算法优化参数，实现10 、15 入射角下碳化硅厚度分别为6.4212μm、6.8031μm，不同角度结果差异仅1.6%；最后，推导多光束干涉的核心必要条件（界面反射率阈值R?R?>0.01、光程差<相干长度），判定硅晶圆数据存在多光束干涉，求解其厚度为10.2212μm（10 ）、10.1772μm（15 ）；若碳化硅受多光束干扰，通过叠加晶圆破坏光程差条件，最终厚度修正为8.463μm（10 ）、8.532μm（15 ）。实验验证表明，该模型测量精度高、场景适应性强，可为半导体材料厚度检测提供技术支撑。Abstract
To address the demand for accurate thickness measurement of silicon carbide (SiC) epitaxial layers, this paper constructs a thickness calculation model suitable for dual-beam and multi-beam scenarios based on infrared reflectance spectroscopy and equal-inclination interference theory. It resolves key issues in traditional measurements, such as interference fringe disturbance and non-constant refractive index. Firstly, a dual-beam interference model is established, and the thickness calculation formula is derived by combining optical path difference and phase difference. Secondly, a third-order Cauchy dispersion model is introduced to describe the refractive index-wavelength relationship, and parameters are optimized using a nonlinear least squares algorithm. The results show that the SiC thicknesses at incident angles of 10 and 15 are 6.4212 μm and 6.8031 μm respectively, with a relative difference of only 1.6%. Finally, the core necessary conditions for multi-beam interference are derived (interface reflectivity threshold R?R? > 0.01, optical path difference < coherence length). It is determined that multi-beam interference exists in silicon wafer data, and the calculated thicknesses are 10.2212 μm (10 ) and 10.1772 μm (15 ). If SiC is affected by multi-beam interference, the optical path difference condition is disrupted by superimposing the wafer, and the final corrected thicknesses are 8.463 μm (10 ) and 8.532 μm (15 ). Experimental verification indicates that the proposed model features high measurement accuracy and strong scenario adaptability, providing technical support for the thickness detection of semiconductor materials.????? 关键词
半导体技术/碳化硅外延层/等倾干涉/多光束干涉/柯西色散模型Key words
Semiconductor Technology/Silicon Carbide (SiC) Epitaxial Layer/Equal-Inclination Interference/Multi-Beam Interference/Cauchy Dispersion Model引用本文复制引用
薛紫涵,刘婧.基于等倾干涉的SiC外延层测厚研究[EB/OL].(2025-11-26)[2025-11-28].http://www.paper.edu.cn/releasepaper/content/202511-21.学科分类
物理学/半导体技术/无线电、电信测量技术及仪器
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