Integration of optically active and diamond-based color centers with semiconductor substrates for quantum devices

A method for fabricating quantum devices, the method comprising:

• receiving a set of three-dimensional stacks, comprising overgrown diamond thin film layers that have been grown onto top surfaces of corresponding diamond substrates;
• etching alignment markers into top surfaces of the overgrown diamond thin film layers;
• implanting ions into the top surfaces of the overgrown diamond thin film layers, wherein the implanting is localized by referencing the alignment markers;
• receiving a semiconductor substrate;
• patterning additional alignment markers onto a top surface of the semiconductor substrate;
• performing flip-chip bonding, wherein the performing the flip-chip bonding comprises:
• aligning the alignment markers on the top surfaces of the overgrown diamond thin film layers to the additional alignment markers on the top surface of the semiconductor substrate;
• and
• bonding, using a deposited bonding layer as an intermediary layer, the top surfaces of the overgrown diamond thin film layers and a top surface of a separate semiconductor substrate to one another;
• removing the diamond substrates;
• and
• etching thru-holes into the top surfaces of the overgrown diamond thin film layers and proximate to the implanted ions, wherein:
• the etching is localized by referencing some combination of the alignment markers and the additional alignment markers;
• and
• the implanted ions and the thru-holes form the quantum devices.

A method for fabricating optically active quantum memories, the method comprising:

• depositing, via chemical vapor deposition, overgrown diamond thin film layers onto top surfaces of corresponding diamond substrates, wherein gaps between respective ones of the overgrown diamond thin film layers within a chemical vapor deposition chamber are determined to ensure uniformity of deposition of the overgrown diamond thin film layers with respect to one another;
• implanting silicon ions into portions of the top surfaces of the overgrown diamond thin film layers;
• performing flip-chip bonding, wherein the performing the flip-chip bonding comprises bonding, using a deposited bonding layer as an intermediary layer, the top surfaces of the overgrown diamond thin film layers and a top surface of a separate semiconductor substrate to one another;
• removing the diamond substrates;
• and
• etching thru-holes into the top surfaces of the overgrown diamond thin film layers and proximate to the implanted silicon ions, wherein the implanted silicon ions and the thru-holes form the optically active quantum memories.