Search for New High-κ Dielectrics by Combinatorial Chemical Vapor Deposition

2003 ◽  
Vol 765 ◽  
Author(s):  
Bin Xia ◽  
Ryan Smith ◽  
Fang Chen ◽  
Stephen A. Campbell ◽  
Wayne L. Gladfelter

AbstractTo develop a high-κ gate dielectric for replacing SiO2 in MOSFETs, multi-component metal oxides could have advantages over single metal oxides because they may offer higher dielectric constants (κ's) as well as other favorable properties. To find the film composition for obtaining a good dielectric from the given component oxides is a time-consuming and costly process for multi-component systems. Recently, we reported a combinatorial chemical vapor deposition (CVD) technique to deposit compositional spreads of ternary metal-oxides for high-κ dielectrics. In this work, compositional spreads of ZrO2, TiO2, SnO2 and HfO2 were deposited using anhydrous metal nitrates. By measuring chemical composition, film thickness, and electrical properties, we are able to map κ and establish its dependence on film composition. This high-throughput deposition technique allows us to generate a compositional library quickly for screening material properties. In addition, a crystalline phase which does not exist in any of the four pure oxides, α-PbO2, was detected.

2006 ◽  
Vol 910 ◽  
Author(s):  
Farhad Taghibakhsh ◽  
K.S. Karim

AbstractFabrication of hot-wire chemical vapor deposition (HWCVD) of amorphous silicon (a-Si) thin film transistors (TFT) on thin polyamide sheets is reported. A single graphite filament at 1500 °C was used for HWCVD and device quality amorphous silicon films were deposited with no thermal damage to plastic substrate. Top-gate staggered thin film transistors (TFTs) were fabricated at 150°C using hot-wire deposited a-Si channel, Plasma enhanced chemical vapor deposition (PECVD) silicon nitride gate dielectric, and microcrystalline n+ drain/source contacts. Low leakage current of 5×10-13 A, high switching current ratio of 1.3×107, and small sub threshold swing of 0.3 V/dec was obtained for TFTs with aspect ratio of 1300μm/100μm. The field effect mobility was extracted to be 0.34 cm2/V.s.


1998 ◽  
Vol 511 ◽  
Author(s):  
Catherine B. Labelle ◽  
Kenneth K. S. Lau ◽  
Karen K. Gleason

ABSTRACTPulsed plasma enhanced chemical vapor deposition films have been grown from C2H2F4, CH2F2, and CHCLF2. C-Is x-ray photoelectron spectroscopy (XPS) indicates a prevalence of C-CF species in the films from C2H2F4 and CH2F2, whereas CF2 species dominate the films from CHC1F2. The CFx species distributions for the films are largely controlled by the competition between CF2-producing and HF elimination reactions in the pulsed plasmas. Dominance by HF elimination produces films with high C-CF and CF concentrations (e.g., CH2F2), whereas dominance by CF2-producing reactions leads to films with higher CF2 concentrations (e.g., CHCIF2). The % CF3 in the film is lowest for the precursor having the lowest F:H ratio, CH2F2. Little or no hydrogen was detected in the deposited films. Thermal degradation of films from C2H2F4 and CH2F2, as probed by solid-state nuclear magnetic resonance (NMR) spectroscopy, shows a loss through CF3 detachment and HF elimination. Pulsed plasma films from all three precursors gave dielectric constants of 2.4, with loss tangents on the order of 10−2. Dielectric measurements of pulsed plasma films from hexafluoropropylene oxide (HFPO) gave a dielectric constant of 2.0 ± 0.1 with a loss tangent of 0.009.


1996 ◽  
Vol 443 ◽  
Author(s):  
S. W. Lim ◽  
M. Miyata ◽  
T. Naito ◽  
Y. Shimogaki ◽  
Y. Nakano ◽  
...  

AbstractOne solution to reduce the time constant of ultra large scale integrated circuit (ULSI) is the use of a low dielectric constant intermetal film like fluorinated silicon oxide (SiOF). We could obtain SiOF films with low dielectric constant as low as 2.6 and good step coverage by adding CF4 to SiH4 and N2O in plasma-enhanced chemical vapor deposition (PECVD) process. To investigate the dielectric constants due to each polarization and the reason for the decrease in the dielectric constant, we used capacitance-voltage (C-V) and ellipsometry measurements, and Kramers-Kronig transformation. The decrease in dielectric constant could not be completely explained by the reduction in ionic and electronic polarization. We could detect silanol groups, Si-OH in the films and their decrease with increasing CF4 flow rate. It is suggested that the main polarization component to decrease dielectric constant is such as orientational polarization. The step coverage of film was improved by adding CF4. It is suggested that the reduction in the sticking probability of films forming species due to the change in surface state improved the step coverage.


1992 ◽  
Vol 284 ◽  
Author(s):  
Ryoichi Ishihara ◽  
Hiroshi Kanoh ◽  
Yasutaka Uchida ◽  
Osamu Sugiura ◽  
Masakiyo Matsumura

ABSTRACTSilicon nitride films have been successfully deposited at a temperature as low as 300°C by chemical-vapor-deposition using tctra-silane (Si4 H10) and hydrogen azidc (HN3). Atomic ratio (N/Si) of the film deposited at 400°C was 1.47, i.e., the film was N-rich. Total hydrogen content was about 25atomic%. The breakdown-field strength was 6.5MV/cm at leakage-current density of 1μA/cm2, and the low-field resistivity was more than 1015 Ωcm. Similar electrical characteristics were obtained from films deposited at a temperature range between 300°C and 500°C. Amorphous silicon thin-film transistors equipped with this film as the gate dielectric showed good transfer characteristics.


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