Development of Epitaxial, Tiling, and Cutting Processes for a Diamond Single Crystal Wafer Technology

Abstract

ABSTRACTDevelopment of a diamond homoepitaxial deposition process that utilizes water and-ethanol at a growth temperature of ∼600°C is described. Topographies are excellent, and etch-pit densities (EPD) are in the 106cm-2range when growth is done on type Ia C(100) substrates.-This process has been used to epitaxially join diamond single crystals that were bonded in close-proximity to each other. This process of “tiling” single crystal diamonds in close proximity in-order to manufacture a large-area diamond single crystal template is also described. Specially-prepared diamonds that have had their faces and edges oriented to { 100} were coated with-heteroepitaxial Ni, then pressed onto a Si wafer while being heated in an inert gas atmosphere.-The resulting bond is excellent; thereby permitting our 600°C diamond deposition process to-epitaxially join the diamonds. A diamond wafer cutting technology has been addressed using a-specific sequence consisting of: ion implantation, homoepitaxial diamond growth, annealing, and-contactless electrochemical etching. This “lift-off” method of cutting has thus far resulted in a 2mm×O.5mm×17.5μm transparent, synthetic, free-standing, single crystal diamond plate being-fabricated. Raman spectroscopy and EPD show the plate to be comparable to our best-homoepitaxial diamond.