Preparation method for boron-doped diamond film

Abstract

The invention relates to a preparation method for a boron-doped diamond film. The preparation method comprises the following steps that after the CVD diamond deposition condition in a deposition cavity meets the deposition requirement, a crucible used for containing elemental boron in the deposition cavity is heated to the sublimation regulation and control temperature for sublimating the elemental boron; and a third corresponding relation between the sublimation regulation and control temperature and the boron concentration in the deposition cavity is determined according to a first corresponding relation between the sublimation regulation and control temperature and the vapor pressure of boron in the deposition cavity and a second corresponding relation between the vapor pressure of theboron in the deposition cavity and the boron concentration in the deposition cavity, and the sublimation regulation and control temperature is adjusted to adjust the boron doping concentration in thedeposition cavity. The doping concentration of a boron source is controlled through the independent sublimation regulation and control temperature under the condition that the CVD diamond deposition condition in the deposition cavity is not changed, it is guaranteed that the deposition and doping effects are good, the control is easy, and the operation is safe and convenient.

Description

technical field [0001] The invention relates to a BDD film preparation technology, in particular to a method for preparing a boron-doped diamond film. Background technique [0002] Boron-doped diamond (BDD) film is a kind of conductive diamond film, which can be widely used in electricity and processing. The key to preparing boron-doped diamond films is to dope boron during the deposition process. There are many methods of boron doping, which can usually be determined according to the form of boron used. Among them, the types of boron sources that can be used for boron doping mainly include gaseous (diborane) , liquid (trimethyl borate) and solid (elemental boron, boron oxide, etc.). However, the gaseous boron source and liquid boron source (including diborane and trimethyl borate) are flammable, explosive, and highly toxic. Therefore, special attention should be paid to prevent accidents caused by leakage during use, and tail gas treatment is required. , security cannot b...

AI Technical Summary

Problems solved by technology

However, the gaseous boron source and liquid boron source (including diborane and trimethyl borate) are flammable, explosive, and highly toxic. Therefore, special attention should be paid to prevent accidents caused by leakage during use, and tail gas treatment is required. , security cannot be guaranteed

The solid-state boron source is relatively the safest in use, but the solid-state boron source, boron oxide, easily absorbs water in the air to form boric acid, and then decomposes water molecules during the deposition process, which will directly cause the hot wire to oxidize and break, causing damage to the equipment

[0003] Therefore, elemental boron is the safest boron source, but the existing elemental boron doping method is to place elemental boron on the sample holder below the hot wire in the hot wire reaction chamber, and under the action of high-temperature hydrocarbon plasma, the elemental boron Boron is first converted into a gaseous boron-containing compound, which enters the source gas for diamond synthesis and is mixed with methane and hydrogen for doping. Among them, it is very difficult to control the concentration of boron, which directly affects the uneven boron content in the diamond crystal. If To change the concentration of boron, it is necessary to change the power of the hot wire, as well as the gas flow rate and the ratio of methane to hydrogen. It will lead to changes in all diamond growth conditions and seriously affect product quality

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