Method for SiC (Silicon Carbide) ohmic contact by using laser irradiation

Abstract

The invention discloses a method for SiC (Silicon Carbide) ohmic contact by using laser irradiation, relating to the technical field of fabrication of a semiconductor device. The method comprises the following steps of: cleaning the surface of a SiC substrate; irradiating from the front side of the substrate or the back side of the substrate by laser in a protective atmosphere of high vacuum, inert gas or inertia liquid; and preparing a contact layer on the surface of the SiC to obtain ohmic contact. Since the performance is changed due to mutual action of the SiC substrate and the laser, an electrode material is deposited on the surface of the substrate and is unnecessary to be subjected to heat treatment so as to directly obtain ohmic contact, the process flow is simplified, the influence of heat treatment on the performance of the contact layer is avoided, and technical support is provided for the improvement on the quality of the semiconductor device using the SiC as the substrate.

Description

technical field

[0001] The invention relates to the technical field of semiconductor device preparation, in particular to a method for preparing SiC ohmic contacts by laser irradiation. Background technique

[0002] Silicon carbide (Silicon Carbide, SiC) is one of the core materials in the third generation of semiconductor materials. In order to develop the potential of SiC materials in the field of high-temperature, high-power and high-frequency semiconductor devices, a key process problem to be solved is to prepare high-stability and low-resistance ohmic contacts. So far, good ohmic contact preparation is still one of the most important and active research aspects for the process of SiC materials.

[0003] Forming an ohmic contact between a metal and a semiconductor means that there is a pure resistance at the contact, and the smaller the resistance, the better. When the metal is deposited on the surface of the semiconductor, due to the existence of the contact barrier, ...

Examples

Embodiment 1

[0013] Use n-type 4H-SiC as the substrate, clean the substrate surface, use a pulsed laser with a wavelength of 248nm and a single pulse energy of 250mJ to focus, and then irradiate the area on the substrate surface that needs to be prepared for ohmic contact in an argon atmosphere, and then A layer of Ni metal is sputtered on the surface of the substrate by magnetron sputtering to obtain an ohmic contact.

Embodiment 2

[0015] Using n-type 4H-SiC as the substrate, the surface of the substrate was cleaned, and focused by a pulsed laser with a wavelength of 248nm at 5×10 -4 In a Pa high vacuum atmosphere, irradiate the area on the surface of the substrate where ohmic contact needs to be prepared, and then sputter a layer of Ti metal on the surface of the substrate by magnetron sputtering to obtain ohmic contact.

Embodiment 3

[0017] Use semi-insulating 4H-SiC as the substrate, clean the substrate surface, use a pulsed laser with a wavelength of 248nm to focus, and then irradiate the area on the substrate surface that needs to be prepared for ohmic contact in an argon atmosphere, and then use magnetron sputtering A layer of Ni metal is sputtered on the surface of the substrate by sputtering to obtain an ohmic contact.

technical field

[0001] The invention relates to the technical field of semiconductor device preparation, in particular to a method for preparing SiC ohmic contacts by laser irradiation. Background technique

[0002] Silicon carbide (Silicon Carbide, SiC) is one of the core materials in the third generation of semiconductor materials. In order to develop the potential of SiC materials in the field of high-temperature, high-power and high-frequency semiconductor devices, a key process problem to be solved is to prepare high-stability and low-resistance ohmic contacts. So far, good ohmic contact preparation is still one of the most important and active research aspects for the process of SiC materials.

[0003] Forming an ohmic contact between a metal and a semiconductor means that there is a pure resistance at the contact, and the smaller the resistance, the better. When the metal is deposited on the surface of the semiconductor, due to the existence of the contact barrier, ...

Examples

Embodiment 1

[0013] Use n-type 4H-SiC as the substrate, clean the substrate surface, use a pulsed laser with a wavelength of 248nm and a single pulse energy of 250mJ to focus, and then irradiate the area on the substrate surface that needs to be prepared for ohmic contact in an argon atmosphere, and then A layer of Ni metal is sputtered on the surface of the substrate by magnetron sputtering to obtain an ohmic contact.

Embodiment 2

[0015] Using n-type 4H-SiC as the substrate, the surface of the substrate was cleaned, and focused by a pulsed laser with a wavelength of 248nm at 5×10 -4 In a Pa high vacuum atmosphere, irradiate the area on the surface of the substrate where ohmic contact needs to be prepared, and then sputter a layer of Ti metal on the surface of the substrate by magnetron sputtering to obtain ohmic contact.

Embodiment 3

[0017] Use semi-insulating 4H-SiC as the substrate, clean the substrate surface, use a pulsed laser with a wavelength of 248nm to focus, and then irradiate the area on the substrate surface that needs to be prepared for ohmic contact in an argon atmosphere, and then use magnetron sputtering A layer of Ni metal is sputtered on the surface of the substrate by sputtering to obtain an ohmic contact.