An rt detector suitable for lattice-mismatched epitaxial materials and its application

Abstract

The invention discloses an RT detector suitable for lattice-mismatched epitaxial materials and its application. The RT detector suitable for lattice-mismatched epitaxial materials includes a light source and several sub-receivers; the several sub-receivers The distribution method is an array distribution; the light source is used to emit incident light, and the incident light propagates to the surface of the peripheral epitaxial wafer to form an optical signal; the sub-receiver is used to receive the optical signal formed by the corresponding epitaxial wafer, and The received optical signal is photoelectrically converted to obtain an electrical signal; it realizes the precise monitoring of the growth temperature during the growth process of the lattice mismatch structure epitaxial wafer.

Description

technical field [0001] The invention relates to the field of growth and preparation of semiconductor materials, in particular to an RT detector suitable for lattice-mismatched epitaxial materials and an application thereof. Background technique [0002] The growth and preparation of epitaxial materials by MOCVD requires precise monitoring of the growth temperature. There are two commonly used monitoring methods, namely (RT) and (TC). Among them, RT is the temperature of the wafer surface, which is realized by monitoring the reflectance curve, and TC is the temperature of the graphite disk, which is detected by a thermocouple. For lattice-mismatched multi-junction cells, during the growth process, in addition to the stress caused by the difference in thermal expansion coefficient between the epitaxial layer material and the substrate under high temperature conditions, the stress introduced by the growth of the lattice-mismatched material will cause the epitaxial wafer to ben...

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Problems solved by technology

For heteroepitaxy materials with a large degree of mismatch with the crystal lattice, in order to ensure the complete relaxation of the lattice of the mismatched material and avoid the increase of lattice dislocations, the composition change rate of the composition gradient buffer layer should not be too fast, so the buffer The thickness of the layers is relatively thick, and the growth time is long. More importantly, because the stress between the lattice mismatched materials is large and it is difficult to be fully released, the overall material deformation is relatively large during the preparation process, causing the reflection signal to deviate from the effective reception. The area is far away, the traditional RT and TC temperature control methods are no longer applicable, and the sudden increase in the calculation amount using the difference comparison method leads to a delay effect. Therefore, the monitoring during the growth of the epitaxial wafer is correspondingly more difficult

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