Preparation method of silicon-based composite substrate for electronic device

Abstract

The invention belongs to the technical field of the preparation of a base material for an electronic device, and specifically provides a method for preparing a silicon-based diamond film composite substrate for an electronic device. The method comprises the following steps: using a silicon substrate with a diameter of 2-8 inches and a thickness of 4-20 millimeters as a matrix for deposition; placing onto a specially-designed stepped heat-conducting cooling body deposition platform; introducing a gaseous mixture of hydrogen gas, argon gas and methane; depositing a diamond film with vacuum arc plasma; relieving the stress of the silicon-based diamond composite substrate; grinding or polishing until the surface roughness is less than 5nm; and cutting to obtain the silicon-based diamond film composite substrate composed of the diamond film with a required thickness and the composite substrate. By using the plasma injection method to deposit the high-quality diamond film on the silicon substrate at a high speed and carrying out deformation correction and stress relieving based on plasma arc and vacuum heat treatment, the invention avoids the possible breakage of the composite substratein the grinding and polishing process, and can obtain the practical silicon-based composite substrate.

Description

technical field [0001] The invention belongs to the technical field of preparing matrix materials for electronic devices, and in particular provides a method for preparing silicon-based diamond film composite substrates for electronic devices. Background technique [0002] CVD diamond film has excellent properties and has broad application prospects in the fields of mechanics, heat, optics, acoustics, electronics and semiconductors, among which the most striking is the application in semiconductors. Diamond has a wide band gap (5.5eV), high carrier mobility, low dielectric constant (5.7), strong radiation resistance, and high breakdown field strength (3.5×10 6 V / cm) and high electron saturation velocity (2.5×10 7 cm / s), which makes it possible to use diamond to make high-frequency and high-power semiconductor devices, which work under harsh conditions such as high temperature and strong radiation. At the same time, its high thermal conductivity can be used as a heat sink f...

AI Technical Summary

Problems solved by technology

In order to have both semiconductor performance and high heat dissipation characteristics at the same time, it has been proved that the diamond film has a certain thickness, generally greater than 25 microns. Although the microwave CVD method deposits diamond films with high quality, the deposition rate is slow and the efficiency is low. Large-area also more difficult

Hot wire CVD and hot cathode methods can achieve large areas but relatively poor quality

[0003] Although the most basic and most suitable choice for depositing diamond films on silicon substrates, the deposition of diamond films on silicon substrates by plasma spraying has been difficult to achieve because the silicon wafers are easily cracked due to the thermal shock of the plasma arc.

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