High-pressure High-temperature (HPHT) Growth Technology for High-quality NV Diamond Substrates

The diamond's nitrogen-vacancy (NV) color center is an essential physical system for emergent quantum technologies. Despite remarkable progress in past years in interfacing NV centers with on-chip electronics, realizing these technologies' full potential requires addressing several materials engineering challenges. It includes a stable commercial supply of large-size diamond wafers with consistent and controllable properties, including high crystallinity, álow-strain, and low background nitrogen doping. Among two competing technologies for lab-grown single crystal diamonds, the CVD technique is well presented in the US and slightly better in controlling purity (5-10 ppb nitrogen level for the best vendors). On the other hand, high-pressure high-temperature (HPHT) diamond growth technology holds more than two orders of magnitude advantage over CVD in terms of high-crystallinity, low-strain substrates. Several research groups worldwide, including Euclid Beamlabs in the US, have demonstrated a low-strain (<0.1 ppm), near the defect-free density of 100/cm2, with defect-free areas over 5x5 mm2.á In this proposal, Euclid Beamlabs will innovate HPHT technology by achieving nitrogen doping levels below 1 ppb and expanding diamond substrates to 10x10 mm▓ area to enhance production yield. This advancement will be facilitated by modifying the reactor design and applying a nitrogen-free environment for growth conditions. áá