To save content items to your account,
please confirm that you agree to abide by our usage policies.
If this is the first time you use this feature, you will be asked to authorise Cambridge Core to connect with your account.
Find out more about saving content to .
To save content items to your Kindle, first ensure email@example.com
is added to your Approved Personal Document E-mail List under your Personal Document Settings
on the Manage Your Content and Devices page of your Amazon account. Then enter the ‘name’ part
of your Kindle email address below.
Find out more about saving to your Kindle.
Note you can select to save to either the @free.kindle.com or @kindle.com variations.
‘@free.kindle.com’ emails are free but can only be saved to your device when it is connected to wi-fi.
‘@kindle.com’ emails can be delivered even when you are not connected to wi-fi, but note that service fees apply.
Local electronic states at nanometer-thick silicon oxide and nitride films on Si can be studied on an unprecedented scale using low - energy cathodoluminescence spectroscopy to observe optical transitions of defect bonding arrangements at ultrathin film interfaces prepared by low -temperature plasma deposition. Our results illustrate significant differences in the dependence of specific defects at the oxide versus nitride interfaces on thermal annealing and hydrogenation.
Mesarjian et al. were the first to recognize the effects of suboxide interfacial transition regions at Si-SiO2 interfaces on tunneling oscillations in the Fowler-Nordheim regime. This paper extends these ideas to the direct tunneling regime and focuses on differences in interfacial transition regions between Si-SO2 interfaces with, and without monolayer level interface nitridation. Tunneling currents in both the direct and Fowler-Nordheim tunneling regimes are reduced by monolayer level interface nitridation for PMOS and NMOS devices with the same oxide-equivalent thickness. This paper develops a modified barrier layer model based on analysis of XPS results that accounts for these reductions in current in the direct tunneling regime.
We have used low energy cathodolumrdinescence spectroscopy (CLS) to characterize defects at ultrathin (50 Å) silicon dioxide films, prepared on Si substrates by low-temperature plasma deposition. Variable-depth excitation with different electron injection energies provided a clear distinction between deep levels localized within the films versus at their interfaces. Defect bands are evident at 0.8 eV and 1.9 eV, characteristic of an amorphous, silicon-rich local bonding environment. Closer to the film surface, CLS reveals a defect at 2.7 eV indicative of oxygen vacancies in stoichiometric SiO2. The effect of hydrogenation at 400°C, rapid thermal annealing at 900°C, and especially the combination of both processing steps is shown to reduce the density of these defects dramatically.
The incorporation of bonded nitrogen into ultra thin SiO2 gate dielectrics has become an important technology issue. Nitrogen atoms bonded in the immediate vicinity of the Si-SiO2 interface improve device reliability in n-channel field effect transistors. N- atom incorporation at the monolayer concentration range has been achieved by remote plasma assisted oxidation in N2O at 300°C. The incorporation mechanism and the stability of bonded-N are discussed.
This paper presents experimental studies in which N-atoms have been incorporated at Si-SiO2 interfaces by forming the interface and oxide film by a 300°C remote plasma assisted nitridation/oxidation process using N2O. Process dynamics have been studied by on-line Auger electron spectroscopy (AES) by interrupted plasma processing. Plasma-activated species have been identified by in-situ mass spectrometry (MS) and optical emission spectroscopy (OES). Based on AES studies using N2O, O2 and sequenced N2O and O2 source gases, reaction pathways for N-atom incorporation i) at and/or ii) removal from buried Si-SiO2 interfaces have been identified, and contrasted with reaction pathways for nitridation using conventional furnace processing. The active species for N-atom incorporation is NO+, and for oxide growth, O2.
During a high RF power (60–100 W) N20/He remote plasma oxidation of Si(100) at 300 °C, nitrogen atoms have been incorporated at the top surface of an ultra-thin (1.0–2.5 nm) oxide. Online Auger electron spectroscopy (AES) has been used to estimate the dielectric film thickness and track the evolution of the film growth. A chemically shifted Si-LW feature from the high RF power oxidation sample indicates that the nitrogen is bonded to the silicon at the top surface of the oxide film. The stability of the bonded nitrogen is also evident in the persistence of the N-KLL Auger peak following (i) a 30 s rapid thermal anneal (RTA) in Ar at 900 °C and (ii) a remotely excited He plasma treatment at 300 °C for 15 s.
Thin film dielectrics have been prepared in a cluster processing system with chambers for plasma-assisted, rapid-thermal processing, and on-line Auger electron spectroscopy (AES). A low-thermal budget process for the formation of homogeneous silicon oxynitride (OXN) alloy films is presented. This Na2-based plasma-CVD process has (i) increased process latitude for the formation of N-rich alloys, and (ii) results in lower bonded-H concentrations, in comparison with a similar NH3-based process. Gate dielectric formation consists of (i) a 300°C plasma-assisted oxidation for removal of residual hydrocarbons, and formation of an Si-SiO2 interface protected by ∼0.5-0.6 nm of oxide, (ii) a 300°C plasma-assisted CVD of oxynitride films from N2O, N2, and SiH4, and (iii) a 30 s, 900°C post-deposition rapid-thermal anneal in an ambient that contains sufficient oxygen to prevent decomposition of the Si/SiO2 interface. On-line AES and off-line infrared (IR) spectroscopy have been used to characterize chemical bonding, showing that the deposited films are pseudo-binary alloys lying on a join-line from SiO2 and Si3N4 in a ternary composition diagram. Electrical characterization of MOS capacitors, consisting of O-OXN-O structures, using C-V techniques is discussed.
We have used a combination of plasma and rapid thermal processing for the formation of thin gate-dielectric films. The bulk dielectric films investigated include silicon oxide, oxynitride and multilayer oxide-nitride-oxide heterostructures formed by plasma-assisted oxidation, remoteplasma-enhanced chemical-vapor deposition (remote-PECVD) followed by post-deposition rapid thermal annealing (RTA). Auger electron spectroscopy (AES) and infrared absorption spectroscopy (IR) have been used to study the chemistry of interface formation and the bulk dielectric chemical bonding, respectively. Electrical characterization of MOS capacitor structures incorporating these dielectrics was performed by conventional capacitance and current voltage techniques, C-V and I-V, respectively.
Email your librarian or administrator to recommend adding this to your organisation's collection.