G.C. Chen

Integration of (PbZr0.52Ti0.48O3) on single crystal diamond as metal-ferroelectric-insulator-semiconductor capacitor

The authors report the integration of ferroelectric Pb(Zr0.52,Ti0.48)O3 (PZT) thin film on single crystal diamond by using Al2O3 as a buffer layer and SrTiO3 as a seed layer. The PZT film exhibits a remanent in-plane polarization of 2Pr=31u2002μC/cm2 and a coercive field of 36 kV/cm. The electrical properties of the metal-ferroelectric-insulator-semiconductor (MFIS) capacitor using boron-doped single crystal diamond epilayer are investigated. The leakage current of the MFIS device is found to be greatly reduced as compared to that of the metal/diamond Schottky diode. Although the overall capacitance-voltage characteristic shows a trap dominated hysteresis behavior, the ferroelectric polarization induced voltage shift is demonstrated under positive gate voltage.

Structures and properties of BON and multilayered TiN/BON thin films prepared by PAMOCVD method

Hard multilayered TiNyBON thin films have been deposited on steel and copper substrates in the deposition temperature range of RT;300 8C by low frequency RF derived plasma assisted MOCVD. Trimethylborate and tetrakisdimethylaminotitanium precursors were used to grow multilayered TiNyBON thin films. We used Ar gas for a plasma source and N gas as a reactive 2 and additional nitrogen source. In this study, we have mainly investigated the relationship between hardness and structures of the coating layers by the effects of deposition parameters such as deposition time and substrate temperature. We found that the microhardness strongly depended on film thickness and structures of the bilayer films. In addition, the sequence of deposition procedure for the TiNyBON bilayers highly affected the hardness. The maximum hardness obtained from TiNyBON bilayer was 30 GPa. 2002 Elsevier Science B.V. All rights reserved.

Comparison of optical and electrical properties of BON and Ti-BON thin films prepared by PAMOCVD method

Abstract We have firstly grown the BON and Ti-BON thin films on Si(1xa00xa00) in the deposition temperature range RT∼500 °C by low frequency radio frequency derived plasma assisted metal organic chemical vapor deposition. Trimethylborate and tetrakis dimethyl amino titanium precursors were used to grow BON and Ti-BON thin films. N 2 gas as additional nitrogen source was used for reactive gas and the plasma source gas was Ar. Comparative studies of electrical and optical properties between BON thin film and Ti-BON thin film were mainly investigated in this study. FT-IR results show that the bond type in the films is very similar to Bue5f8Oue5f8N and prefer to angular structure rather than linear one. UV/Vis results show that BON is semiconductor material with 3.4 eV of wide band-gap, and PL results show that the optical band-gap is 3.5 eV. It means that the conduction band-gap is less than the optical band-gap. Thus, the BON film gained in this case was a band-structured material with heavy doping. In terms of the I – V curve and film thickness, the electric conductivity is deduced as 8×10 −2 (Ω·cm) −1 , which is as same order-magnitude as 4.3×10 −2 (Ω·cm) −1 measured by four-points probe method. This means that the BON thin films could have a semiconductor nature. Similar results as BON were also obtained from Ti-BON thin films grown under the same deposition condition. However, we found that electrical and optical properties of the as-grown Ti-BON thin films were strongly dependent by nitrogen flux and growth time. Typically, the electrical resistance was decreased with increasing the nitrogen flux and growth time.

Growth of a New Ternary BON Crystal on Si(100) by Plasma-Assisted MOCVD and Study on the Effects of Fed Gas and Growth Temperature

A new ternary BOxNy crystal was grown on Si(100) substrate at 500°C by low-frequency (100 kHz) radio-frequency (rf) derived plasma-assisted MOCVD with an organoborate precursor. The as-grown deposits were characterized by SEM, TED, XPS, XRD, AFM and FT-IR. The experimental results showed that BOxNy crystal was apt to be formed at N-rich atmosphere and high temperature. The decrease of hydrogen flux in fed gases was of benefit to form BON crystal structure. The crystal structure of BOxNy was as similar to that of H3BO3 in this study.

Synthesis and characterization of BON thin films using low frequency RF plasma enhanced MOCVD: effect of deposition parameters on film hardness

With the expectation of getting hard material, we have firstly grown the BON thin film by radio frequency plasma enhanced metal-organic chemical vapor deposition with 100 kHz frequency and trimethyl borate precursor. The plasma source gases used in this study were Ar and H , and two kinds of nitrogen source gases, N and NH , were also employed. The as-grown films 22 3 were characterized with XPS, IR, SEM and Knoop microhardness tester. The film growth rate was influenced both by substrate temperature and by nitrogen source gas. It decreased with increasing the substrate temperature, and was higher by using NH 3 rather than by N . The hardness of the film was dependent on several factors such as nitrogen source gas, substrate temperature 2 and film thickness due to the variation of the composition and the structure of the film. Both nitrogen and carbon-content could raise the film hardness, on which nitrogen content had stronger effect than carbon. The smooth morphology and continuous structure yielded high hardness. The maximum hardness of BON film was approximately 10 GPa. 2003 Elsevier Science B.V. All rights reserved.