Development of a "Clamshell" cavity and niobium substrate holder to optimize the growth of single crystal CVD diamond via microwave MWPACVD technique

Abstract

The aim of this research project is to develop a new pre-industrial production process for laboratory grown monocrystalline diamonds using chemical vapour deposition (CVD). This represents an increase in technology readiness from TRL 5 - the current stage of development - to TRL 7, which involves the construction and operation of a pilot plant in a relevant operational environment. This initiative is pioneering in the Southern Hemisphere and has the potential to introduce a disruptive technology to the global market. The context and rationale for the project is anchored in the growing demand for lab-grown diamonds, driven by applications such as jewellery, but more importantly by the need for technological advances for future applications of diamond CVD in semiconductor devices, high performance optics and heat sinks, nuclear batteries and quantum computing. The objectives of the project include the computational simulation, design and fabrication of a chamber with a resonant microwave propagation cavity at 2.45 GHz, "clamshell" design and other supporting devices; and the performance of diamond CVD growth tests in the pilot plant, focusing on the development and optimisation of process parameters such as chamber internal pressure, substrate temperature, plasma density and gas composition. The development methodology involves a series of steps from literature review to analysis and characterisation of diamond CVD growth test results using advanced materials characterisation techniques. The project includes the purchase of equipment and consumables as well as the construction and testing of the pilot plant. The total project budget is approximately R$1.5 million, with a company contribution of R$350,000 and an angel investor. Expected outcomes include the production of functional prototypes of both the resonant cavity and high quality lab-grown diamond CVD with atomic level colour centres (gems), pioneering technology development via MWPACVD (Microwave Plasma Assisted Chemical Vapor Deposition) and positioning the company in the lab-grown diamond market, potentially competing with major players such as ABD Diamonds, Clean Origin, Element Six (De Beers Group) and Diamond Foundry Inc. The project allows the company to establish itself as a leader in the lab-grown diamond market in the Southern Hemisphere, and secures the use of monocrystalline diamond CVD as a basic material for advanced studies in future-oriented areas such as nuclear batteries, semiconductor devices, quantum computing, high-performance heat sinks and more. (AU)