The ECR-Plasma Deposition of Silicon Nitride on a Tunnel Oxide

1991 ◽  
Vol 223 ◽  
Author(s):  
J. C. Barbour ◽  
H. J Stein ◽  
C. A. Outten

ABSTRACTGate dielectric-quality silicon nitride films were deposited on a tunnel oxide from an SiH4/N2 gas mixture using an electron cyclotron resonance (ECR) plasma. Electrical characteristics depend not only upon the quality of the nitride film but also upon the state of the interfacial oxide. Quasi-static and 1 MHz capacitance-voltage measurements show that a nitride film deposited at 200°C on 2 nm thick thermally-grown oxide (tunnel oxide) on an unbiased Si substrate have an interface state density of l.5×1011/cm2-eV. Time-of-flight elastic recoil detection (TOF-ERD) was used to examine the level of mixing between the tunnel oxide and the deposited silicon nitride as a function of bias voltage. TOF-ERD showed that for an applied bias of −350 V (ion energy ≈ 380 eV), the deposition of a 10 nm thick film was completely mixed to form an oxynitride whereas the tunnel oxide remained intact for an unbiased sample. (Interdiffusion resulting from energetic-beam heating was ruled-out as a possibility for the mixing.)

1992 ◽  
Vol 284 ◽  
Author(s):  
J. C. Barbour ◽  
S. A. Casalnuovo ◽  
S. R. Kurtz

ABSTRACTA combination of Electron Cyclotron Resonance (ECR) plasma, electrochemical, and chemical growth process were examined to synthesize dielectric surface passivation layers on InSb. The material properties of ECR-grown SiOx Ny on InSb at temperatures from 30°C to 250°C were investigated. Composition analysis was done using Rutherford backscattering spectrometry (RBS) and elastic recoil detection (ERD). The electrical quality of the passivation layer was characterized with capacitance-voltage (C-V) measurements on metal-insulator-semiconductor structures over the frequency range from 1 kHz to 1 MHz. Sulfided layers, Si3ON2 on InSb, and sulfided layers capped with S3ON2 all exhibited good C-V properties consistent with interface state densities on the order of 1011/cm2-eV, and flatband voltages of magnitude less than 1 V. The difference in adhesion of Si3N4 on InSb and the adhesion of Si3ON2 on InSb was described in terms of the strength of the bonding at the dielectric-InSb interface. This work is the first to demonstrate passivation of an InSb surface with high-quality ECR silicon oxynitrides grown at room temperature.


2002 ◽  
Vol 716 ◽  
Author(s):  
Parag C. Waghmare ◽  
Samadhan B. Patil ◽  
Rajiv O. Dusane ◽  
V.Ramgopal Rao

AbstractTo extend the scaling limit of thermal SiO2, in the ultra thin regime when the direct tunneling current becomes significant, members of our group embarked on a program to explore the potential of silicon nitride as an alternative gate dielectric. Silicon nitride can be deposited using several CVD methods and its properties significantly depend on the method of deposition. Although these CVD methods can give good physical properties, the electrical properties of devices made with CVD silicon nitride show very poor performance related to very poor interface, poor stability, presence of large quantity of bulk traps and high gate leakage current. We have employed the rather newly developed Hot Wire Chemical Vapor Deposition (HWCVD) technique to develop the a:SiN:H material. From the results of large number of optimization experiments we propose the atomic hydrogen of the substrate surface prior to deposition to improve the quality of gate dielectric. Our preliminary results of these efforts show a five times improvement in the fixed charges and interface state density.


Electronics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 1858
Author(s):  
Matthew Whiteside ◽  
Subramaniam Arulkumaran ◽  
Yilmaz Dikme ◽  
Abhinay Sandupatla ◽  
Geok Ing Ng

AlGaN/GaN metal-insulator-semiconductor high-electron-mobility transistors (MISHEMT) with a low-temperature epitaxy (LTE)-grown single crystalline AlN gate dielectric were demonstrated for the first time and the post-gate annealing effects at 400 °C were studied. The as-deposited LTE-AlN MISHEMT showed a maximum drain current (IDmax) of 708 mA/mm at a gate bias of 4 V and a maximum extrinsic transconductance (gmmax) of 129 mS/mm. The 400 °C annealed MISHEMT exhibited an increase of 15% in gmmax, an order of magnitude reduction in reverse gate leakage and about a 3% suppression of drain current (ID) collapse. The increase of gmmax by post-gate annealing is consistent with the increase of 2DEG mobility. The suppression of ID collapse and the reduction of gate leakage current is attributed to the reduction of interface state density (5.0 × 1011 cm−2eV−1) between the AlN/GaN interface after post-gate annealing at 400 °C. This study demonstrates that LTE grown AlN is a promising alternate material as gate dielectric for GaN-based MISHEMT application.


2007 ◽  
Vol 996 ◽  
Author(s):  
Rajat Mahapatra ◽  
Amit K. Chakraborty ◽  
Peter Tappin ◽  
Bing Miao ◽  
Alton B. Horsfall ◽  
...  

AbstractHfO2 films were grown on SiO2/4H-SiC and SiON/4H-SiC layers by evaporation of metallic Hf in an electron beam deposition system followed by thermal oxidation. X-ray photoelectron spectroscopy confirmed the formation of HfO2 films. There is no evidence of formation of hafnium silicide or carbon pile up at the surface as well as at the interfacial layer. Electrical measurements show the presence of fewer slow traps in the HfO2/SiON gate dielectric stack on 4H-SiC and comparable values of interface state density. The HfO2/SiON stack layer improves leakage current characteristics with a higher breakdown field and has better reliability under electrical stress.


1993 ◽  
Vol 316 ◽  
Author(s):  
J. C. Barbour ◽  
M. L. Lovejoy ◽  
C. I. H. Ashby ◽  
A. J. Howard ◽  
J. S. Custer ◽  
...  

ABSTRACTThe growth of high-quality dielectric films from Electron Cyclotron Resonance (ECR) plasmas provides for low-temperature surface passivation of compound semiconductors. Silicon nitride (SiNx) films were grown at temperatures from 30°C to 250°C on GaAs substrates. The stress in the films was measured as a function of bias applied during growth (varied from 0 to 200 V), and as a function of sample annealing treatments. Composition profiles of the samples were measured using ion beam analysis. The GaAs photoluminescence (PL) signal after SiNx growth without an applied bias (ion energy = 30 eV) was twice as large as the PL signal from the cleaned GaAs substrate. The PL signal from samples biased at -50 and -100 V indicated that damage degraded the passivation quality, while atomic force microscopy of these samples showed a three fold increase in rms surface roughness relative to unbiased samples. The sample grown with a bias of-200 V showed the largest reduction in film stress but also the smallest PL signal.


1997 ◽  
Vol 504 ◽  
Author(s):  
J. C. Barbour ◽  
B. G. Potter

ABSTRACTHydrogen in deposited optical ceramics can modify the optical properties, and therefore the role of the hydrogen needs to be understood to control its effects. Erbium-doped amorphous alumina films were deposited using simultaneous electron beam evaporation of aluminum and erbium while bombarding the sample with 30 eV 02+ ions from an electron cyclotron resonance (ECR) plasma. The hydrogen content was measured, using elastic recoil detection, as a function of isochronal annealing treatments. The data was fit to a simple trap-release model in order to determine an effective activation energy for the thermal release of H from alumina and Er-doped alumina. The intensity of the ion-beam stimulated luminescence from these samples was monitored in the visible and near infrared regions as a function of the thermal treatments. In order to gain a better understanding of the influence of hydrogen, the ionoluminescence (IL) data from samples containing hydrogen were fit with a simple linear equation.


1991 ◽  
Vol 235 ◽  
Author(s):  
J. C. Barbour ◽  
H. J. Stein

ABSTRACTThe incorporation of hydrogen into silicon nitride films grown downstream from an electron cyclotron resonance (ECR) plasma decreased rapidly with increasing substrate temperature (100–600°C). Fourier transform infra-red (FTIR) spectroscopy showed that the hydrogen in the as-grown material was primarily bonded to nitrogen. However, an applied bias of -200 V caused an increase in the number of Si-H bonds relative to N-H bonds, as a result of increased ion-beam damage. In addition, ion irradiation of an as-grown film with 175 keV Ar+ at room temperature showed that H transferred from N-H bonds to Si-H bonds without a loss of H. Elastic recoil detection (ERD) and FTIR of thermally annealed films showed that the stability of H incorporated during deposition increased with deposition temperature, and that the N-H bond was more stable than the Si-H bond above 700°C. Deuterium plasma treatments, at 600°C, of annealed films caused isotopic substitution with a conservation of bonds. Therefore, hydrogen loss from annealed films is apparently accompanied by a reduction in dangling bonds.


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