COLOURLESS DIAMOND LAYER Russian patent published in 2011 - IPC C30B25/02 C30B29/04 C23C16/27 

FIELD: chemistry.

SUBSTANCE: method involves preparation of a substrate, using a HOPF-synthesis atmosphere which contains nitrogen in concentration of over 300 parts per billion (ppb), and adding to the synthesis atmosphere a second gas which contains silicon atoms as dopant atoms of a second type, where dopant atoms of the second type are added in a controlled manner in an amount which ensures reduction of negative effect of nitrogen on colour, where the layer of monocrystalline diamond has thickness of greater than 0.1 mm, concentration of silicon in the dominant volume of the diamond layer is less than or equal to 2·10¹⁸ atoms/cm³, concentration of nitrogen in the dominant volume of the diamond layer is greater than 2·10¹⁶ atoms/cm³ and less than or equal to 2·10¹⁷ atoms/cm³, and the ratio of concentration of nitrogen to concentration of silicon in the dominant volume of the diamond layer is between 1:20 and 20:1. Addition of a source gas which contains silicon counters the negative effect of nitrogen contained in the HOPF-synthesis atmosphere on the colour of the diamond.

EFFECT: obtaining high-purity colourless diamond with low optical absorption.

12 cl, 6 tbl, 9 ex, 3 dwg