Two types of a trench with conventional vertical and new reverse-V-shaped cross-sections were fabricated on single crystal diamond (SCD) substrate using a micro-jet water-assisted laser. In addition, a microwave plasma chemical vapor deposition device was used to produce multiple micrometer-sized channels using the epitaxial lateral overgrowth technique. Raman and SEM methods were applied to analyze both types of growth layer characterization. The hollowness of the microchannels was measured using an optical microscope. According to the findings, the epitaxial lateral overgrowth layer of the novel reverse-V-shaped trench produced improved SCD surface morphology and crystal quality.

In this work, hydrogen-terminated diamond (H-diamond) metal-oxide-semiconductor field-effect-transistors (MOSFETs) on a heteroepitaxial diamond substrate with an Al₂O₃ dielectric and a passivation layer were characterized. The full-width at half maximum value of the diamond (004) X-ray rocking curve was 205.9 arcsec. The maximum output current density and transconductance of the MOSFET were 172 mA/mm and 10.4 mS/mm, respectively. The effect of a low-temperature annealing process on electrical properties was also investigated. After the annealing process in N₂ atmosphere, the threshold voltage (V_th) and flat-band voltage (V_FB) shifts to negative direction due to loss of negative charges. After annealing at 423 K for 3 min, the maximum value of hole field effective mobility (μ_eff) increases by 27% at V_th − V_GS = 2 V. The results, which are not inferior to those based on homoepitaxial diamond, promote the application of heteroepitaxial diamond in the field of electronic devices.

Two types of trenches cross-section in conventional vertical and brand new reverse-V-shape have fabricated on SCD substrate by micro-jet water-assist laser, the epitaxial lateral overgrowth technique has applied by microwave plasma chemical vapor deposition system in forming multiple micrometer-size channels. Raman and SEM techniques have applied in analyze both types growth layer characterization. Optical microscope has used to test microchannels hollowness. As a result, with the brand new reverse-V-shape trench, epitaxial lateral overgrowth layer reaches higher SCD surface morphology and crystal quality.

In this study, nitrogen-vacancy center emissions from nanocone structures fabricated on diamond surfaces by gold film annealing and inductively coupled plasma etching techniques were characterized. First, the diamond substate deposited with gold film was annealed to form a nano-sized dot mask. Second, through inductively coupled plasma etching, nanocone-shaped structures were fabricated using optimized gold dots as masks. Finally, the as-fabricated nanocone and planar structures were investigated with photoluminescence experiments at temperatures ranging from room temperature to 80 K, with the results showing approximately two-fold higher emission values for nitrogen-vacancy centers from nanocones.

We report the fabrication of bottom gate a-IGZO TFTs based on HfO₂ stacked dielectrics with decent electrical characteristics and bias stability. The microscopic, electrical, and optical properties of room temperature deposited a-IGZO film with varied oxygen content were explored. In order to suppress the bulk defects in the HfO₂ thin film and hence maximize the quality, surface modification of the SiN_x film was investigated so as to achieve a more uniform layer. The root mean square (RMS) roughness of SiN_x/HfO₂/SiN_x (SHS) stacked dielectrics was only 0.66 nm, which was reduced by 35% compared with HfO₂ single film (1.04 nm). The basic electrical characteristics of SHS-based a-IGZO TFT were as follows: V_th is 2.4 V, μ_sat is 21.1 cm² V⁻¹ s⁻¹, I_on/I_off of 3.3 × 10⁷, I_off is 10⁻¹¹ A, and SS is 0.22 V/dec. Zr-doped HfO₂ could form a more stable surface, which will decrease the bulk defect states so that the stability of device can be improved. It was found that the electrical characteristics were improved after Zr doping, with a V_th of 1.4 V, I_on/I_off of 10⁸, μ_sat of 19.5 cm² V⁻¹ s⁻¹, I_off of 10⁻¹² A, SS of 0.18 V/dec. After positive gate bias stress of 10⁴ s, the ΔV_th was decreased from 0.43 V (without Zr doping) to 0.09 V (with Zr doping), the ΔSS was decreased from 0.19 V/dec to 0.057 V/dec, respectively, which shows a meaningful impact to realize the long-term working stability of TFT devices.