ICP dry-type cleaning method capable of increasing ashing rate of photoresist

Abstract

The invention discloses an ICP dry-type cleaning method capable of increasing the ashing rate of a photoresist. The ICP dry-type cleaning method comprises the following steps of: 1) spin-coating a layer of the photoresist with a thickness of 1.0 to 3.0 microns on the polished sapphire surface, exposing the photoresist, and developing to obtain a photoresist mask with a regular graphical array; 2) etching the sapphire substrate by ICP to obtain a graphical sapphire substrate; 3) carrying out ashing treatment; 4) cleaning by the mixed solution of sulphuric acid and hydrogen peroxide; 5) carrying out epitaxial layer growth. The invention discloses a novel dry-type cleaning method capable of increasing the ashing rate of a photoresist and simplifying a cleaning step after ICP: charging the mixed gas with a certain flow ratio, of O2 and SF6 after the sapphire graphical etching, wherein the flow of SF6 occupies 5-15% of a total gas flow, in this way, an oxygen atom concentration in plasmas, and the generated amount of the activated photoresist can be effectively improved, and the increasing ashing rate of the photoresist can be increased, thus effectively improving the capacity of removing the photoresist after ion implantation.

Description

technical field [0001] The invention belongs to the technical field of cleaning LED graphic substrate materials, and mainly relates to a dry cleaning method for improving the ashing rate of patterned sapphire substrate photoresist and simplifying the cleaning step after ICP. Background technique [0002] In the traditional patterned sapphire substrate ICP etching process, a certain flow of O is usually introduced after the pattern is etched. 2 , ashing the remaining photoresist to improve the cleanliness of the surface of the PSS sample. Since the main components of photoresists are resins, photosensitive materials and organic solvents, their molecular structures are all organic compounds composed of long-chain C, H, O, and N. Use O 2 Ashing treatment is to use the highly reactive oxygen atoms in the oxygen plasma to react with the carbon, hydrogen and oxygen polymers in the photoresist to generate CO, CO 2 、H 2 O, N 2 And other volatile substances, and finally achieve ...

AI Technical Summary

Problems solved by technology

However, after high-energy ion implantation or high-density plasma dry etching, the photoresist is often prone to local hardening, and only O 2 Insufficient reaction to remove hardened photoresist leaving residue

These residues are usually removed by two acid washes and one ultrasonic alkali wash, but the removal effect is not good. After AOI (Automatic Optic Inspection, automatic optical inspection) detection, the total amount of residual particles below 200 μm is no less than 30-40

These residual particles will seriously affect the crystal quality during epitaxial growth, and even cause the failure of the entire chip