GaAs/Si epitaxial material preparation method

Abstract

The invention relates to the technical field of semiconductor manufacturing and design, and in particular relates to a GaAs/Si epitaxial material preparation method which comprises the following steps: selecting a single crystal Si substrate, and washing the single crystal Si substrate; forming a concave layer on the single crystal Si substrate; forming an Si film layer on the concave layer, and suspending the Si film layer in the groove of the concave layer; forming a GaAs seed layer on the Si film layer; forming a first GaAs buffer layer on the GaAs seed layer; forming a GaAs second buffer layer on the first GaAs buffer layer; and forming a GaAs epitaxial layer on the second GaAs buffer layer. By adopting the method, the high-quality GaAs crystal film can be prepared on the single crystal Si substrate which is low in price, and moreover an additional stress field is not introduced, so that additional adverse influence on quality of devices can be avoided in later device manufacturing.

Description

[0001] Technical field: [0002] The invention relates to the technical field of semiconductor manufacturing and design, in particular to a GaAs / Si epitaxial material preparation method. Background technique [0003] Due to its unique physical and chemical properties (direct band gap, band gap matching with the solar spectrum, high light absorption coefficient, etc.), GaAs thin films have attracted more and more attention. controlled sputtering, chemical vapor deposition, and molecular beam epitaxy. Due to the cheap Si material, mature technology, and large-diameter wafers, there are currently many applications based on Si materials. Silicon-based microelectronic devices continue to promote the rapid development of modern information technology. Epitaxial growth on Si-based GaAs thin film is beneficial to cost reduction and device integration. However, the lattice matching between GaAs and silicon materials is poor, and GaAs materials directly prepared on Si substrates will ...

AI Technical Summary

Problems solved by technology

In the prior art, there are reports of using molecular beam epitaxy (Molecular BeamEpitaxy, MBE) to grow In(Ga)As quantum dot dislocation barriers to reduce the dislocation density of GaAs / Si epitaxial materials, but the growth rate is slow and multilayer In(Ga)As quantum dot dislocation barrier layer will accumulate strong compressive strain energy in GaAs / Si epitaxial materials, so that the prepared materials have greater stress

Chinese Invention Patent Publication No. 201410514645.7 introduces a MOCVD preparation method of GaAs / Si epitaxial materials. The propagation direction of dislocations in the epitaxial materials is changed through a multi-layer quantum dot dislocation barrier layer to reduce dislocations. The process is: using MOCVD Method A GaAs low-temperature nucleation layer, medium-temperature buffer layer, first high-temperature buffer layer, second high-temperature buffer layer, temperature-variable buffer layer, multi-layer quantum dot dislocation barrier layer and strain insertion layer were sequentially grown on a clean single crystal silicon substrate , and finally grow the GaAs epitaxial layer, the process is complicated, and although the strain energy of the multilayer quantum dot dislocation barrier layer can be balanced by the tensile stress of the strained superlattice, thereby reducing or eliminating the total strain energy of the material, it is still There are stress worries

Therefore, the method of reducing dislocations in the epitaxial material by the stress field is prone to cracks in the subsequent device fabrication and reduces the quality of the device.

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