Low Thermal Budget Growth of Near‐Isotropic Diamond Grains for Heat Spreading in Semiconductor Devices

Abstract

The ever-increasing power density is a major trend for electronics applications from dense computing to 5G/6G networks. Joule heating and resulting high temperature in the device channel due to the increased power density results in performance degradation and premature failure. Diamond integration near the hot spot can spread the heat by increasing the heat transfer coefficient. Diamond is mostly grown at high temperatures (700-1000 °C), which limits its integration with many semiconductor technologies. Here, a high-quality 400 °C-diamond by modifying the gas chemistry at different nucleation stages, with a sharp sp 3 Raman peak (FWHM≈6.5 cm −1 ) and high phase purity (97.1%), similar to 700 °C-diamond (>98%) is demonstrated. An average grain size of 650 nm with a thickness of 790 nm corresponding to an anisotropy ratio of 1.21 at 400 °C close to the best-reported of 1.12 at 700 °C is achieved. This near-isotropic diamond exhibits a relatively high thermal conductivity of ≈300 W m −1 K −1 and a thermal boundary resistance as small as only 5 m 2 K G −1 W −1 (on SiO 2 and Si 3 N 4 ). Achieving such a high-quality diamond at 400 °C demonstrates the possibility to grow the diamond on a wide range of semiconductors including Si, InP, Ga 2 O 3 , SiC, and GaN where SiO 2 or its variations, and Si 3 N 4 are commonly used dielectrics.

From wide to ultrawide-bandgap semiconductors for high power and high frequency electronic devices

“…Low temperature (LT) diamond growth has been reported in a temperature range from 100 • C to 500 • C. The growth of a high-quality PC diamond at back end of line compatible temperature, 400 • C, was achieved by modifying the gas chemistry at different nucleation stages. A sharp sp 3 Raman peak (full width at half maximum ≈ 6.5 cm −1 ) and high phase purity (97.1%), like that of HT-diamond (>98%) were measured in the near-isotropic PC diamond [341]. Furthermore, the LT diamond exhibited a relatively high in-plane and cross-plane TC of ∼300 W (m•K) −1 , and a TBR as small as 5 m 2 K (GW) −1 .…”

Low-Temperature Deposition of Diamond Films by MPCVD with Graphite Paste Additive

“…MPCVD in varied gas compositions has been reported. For example, H 2 -CH 4 [9], H 2 -CH 4 -CO 2 [10], H 2 -CH 4 -O 2 [11][12][13][14], CH 4 -CO 2 [15], and H 2 -CH 4 -Ar [16] were used. Microwave plasma produces C, H, and O-containing radicals, which play essential roles in the deposition of diamond and etching of non-diamond carbon phases.…”

On‐chip Diamond MEMS Magnetic Sensing through Multifunctionalized Magnetostrictive Thin Film

“…Single‐crystal diamond (SCD) is a promising material for high‐performance and high‐reliability MEMS devices owing to its outstanding physical, chemical, mechanical, and electrical properties. [ 30–42 ] SCD MEMS resonators combined with galfenol (FeGa), a material with a large magnetostrictive coefficient of 375 ppm and an ultrahigh Curie temperature of 675°C, provide an ideal scheme for high‐sensitivity and thermal‐stability magnetic transducers via the delta‐E (Δ E ) effect. [ 43,44 ] To achieve highly integrated high‐sensitivity SCD MEMS transducers, all‐electrical on‐chip actuation and sensing are required.…”

“…Single-crystal diamond (SCD) is a promising material for high-performance and high-reliability MEMS devices owing to its outstanding physical, chemical, mechanical, and electrical properties. [30][31][32][33][34][35][36][37][38][39][40][41][42] SCD MEMS resonators combined…”