Relationship between Interfacial Roughness and Dielectric Reliability for Silicon Oxynitride Gate Dielectrics Processed with Nitric Oxide

1999 ◽  
Vol 567 ◽  
Author(s):  
J. Sapjeta ◽  
M. L. Green ◽  
J. P. Chang ◽  
P. J. Silverman ◽  
T. W. Sorsch ◽  
...  
Keyword(s):  
Nitrogen Content ◽  
Thermal Process ◽  
Dielectric Film ◽  
Gate Dielectrics ◽  
Silicon Oxynitride ◽  
Interface Roughness ◽  
Concomitant Increase ◽  
Dielectric Interface ◽  
Nitrogen Incorporation ◽  
Order Of Magnitude

ABSTRACTThe greatest benefits of nitrogen incorporation into gate dielectrics may be obtained by placing nitrogen preferentially at the interfacial regions of the dielectric film. One method of distributing nitrogen in this manner is by using a three-step thermal process consisting of 1.) oxynitridation in NO, 2.) subsequent reoxidation in O2, and 3.) a final NO anneal. This study investigates the effect of NO processing on substrate/dielectric interface roughness and correlates that roughness with dielectric reliability. The initial NO-containing step can roughen the interface, as can subsequent reoxidation. Increased NO exposure yields a greater nitrogen content and a concomitant increase in interface roughness. These films show a degradation in charge to breakdown (Qbd) of at least an order of magnitude when compared with similarly prepared O2-oxide films. An O2/NO process produces films with interface roughness and Qbd comparable to that of pure SiO2, independent of nitrogen content. The oxynitride reliability depends on the exact scheme for incorporating nitrogen into SiO2.

Structure and Growth of N2O Gate Oxynitrides

1996 ◽  
Vol 428 ◽  
Author(s):  
K. A. Ellis ◽  
E. C. Carr ◽  
R. A. Buhrman
Keyword(s):  
Flow Rate ◽  
Atomic Oxygen ◽  
Gate Dielectrics ◽  
Total Concentration ◽  
Nitrogen Sources ◽  
Interface State ◽  
Silicon Oxynitride ◽  
Nitrogen Incorporation ◽  
Exothermic Decomposition ◽  
State Generation

AbstractA series of investigations have been conducted into the properties of N2O silicon oxynitride gate dielectrics, and the various methods of their growth. One of the principle advantages of these oxides is their resistance to interface state generation. This is linked to the presense of nitrogen near the substrate interface, where it is triply bonded to silicon. It is also demonstrated that during N2O-based furnace growth, the total concentration of NOx species varies strongly with the flow rate of N2O. This has been correlated to the temperature profile of the furnace, which can be affected by the exothermic decomposition of N2O. This property has been exploited to controllably adjust the rate of nitrogen incorporation by up to a factor of three. Although nitrogen incorporation during furnace processing is generally stable, it is shown that atomic oxygen is capable of removing previously incorporated nitrogen. Sources of atomic oxygen include the decomposition of N2O during RTP treatment, N2O processing in a high flow rate furnace, or from ozone annealing.

Photoemission Study of Interfacial Oxidation in ZrO2/subnanometer SiONx/Si(100) Stacked Structures

2002 ◽  
Vol 747 ◽  
Author(s):  
Seiichi Miyazaki ◽  
Hiroki Yamashita ◽  
Hiroshi Nakagawa ◽  
Masanori Yamaoka
Keyword(s):  
Nitrogen Content ◽  
Oxide Layer ◽  
Barrier Layer ◽  
Oxide Thickness ◽  
Silicon Oxynitride ◽  
Experimental Fact ◽  
Nitrogen Incorporation ◽  
Ft Ir ◽  
Photoemission Study ◽  
Interfacial Oxidation

ABSTRACTFor staked structures consisting of evaporated ZrO2 and ∼0.6nm-thick silicon oxynitride formed on Si(100), the blocking capability of the silicon oxynitride against oxidation in dry-O2 anneal at 500°C has been studied as a function of nitrogen content in the barrier layer in the range within ∼11at.%. With increasing nitrogen content, the interfacial oxide thickness is decreased linearly and, to suppress the growth of the interfacial oxide layer within two monolayers, a nitrogen content of ∼10at.% is necessary. Observed efficient blocking against oxidation, even for the case with a nitrogen content as small as ∼6at.%, is attributable to the improved homogeneity in the Si-O-Si bonding features at the interface by nitrogen incorporation of a few at.%, which is suggested from the experimental fact that the bandwidth of LO phonons near the interface due to the nitrogen incorporation is decreased as obtained by FT-IR-ATR measurements.

Improved Performance and Reliability in Aggressively-Scaled NMOS and PMOS FETs: i) Monolayer Interface Nitridation, and ii) Replacement of Stacked Oxide/Nitride Dielectrics With Optimized Oxide/Oxynitride Stacks

1999 ◽  
Vol 592 ◽  
Author(s):  
Hanyang Yang ◽  
Hiro Niimi ◽  
Gerry Lucovsky
Keyword(s):  
Second Generation ◽  
Gate Dielectrics ◽  
Tunneling Current ◽  
Silicon Oxynitride ◽  
Improved Performance

ABSTRACTThis paper demonstrates optimized performance and reliability in ‘second generation’ gate dielectrics which include monolayer nitrided Si-SiO2 interfaces, and deposited silicon oxynitride alloy gate dielectrics. Devices with oxynitride alloy gate dielectrics with an approximate 2:1 ratio of N:O display reduced tunneling current, improved hole mobilities and improved reliability compared to devices with Si-nitride gate dielectrics and the same nitrided interface.

Microroughness at the Si/SiO2 Interface from Pre-Oxidation Annealing, Measured Using Quantum Oscillations in Fowler-Nordheim Tunneling Currents

1992 ◽  
Vol 280 ◽  
Author(s):  
J. C. Poler ◽  
K. K. McKay ◽  
E. A. Irene
Keyword(s):  
Gate Dielectrics ◽  
Interface Roughness ◽  
Quantum Oscillation ◽  
Interfacial Region ◽  
Mos Capacitors ◽  
Quantum Oscillations ◽  
High Temperature Anneal ◽  
Afm Imaging ◽  
Tunneling Currents ◽  
Nordheim Tunneling

ABSTRACTAs design rules shrink to conform with ULSI device dimensions, gate dielectrics for MOSFET structures are required to be scaled to even thinner proportions. Upon scaling the gate oxides below ∼60Å some properties of the device, such as interface roughness, that are negligible for thicker films become critical and must be evaluated. Microroughness at the interface of ultrathin MOS capacitors has been shown to degrade these devices.We are studying the interfacial region of ∼50Å SiO2 on Si using the quantum oscillations in Fowler-Nordheim tunneling currents. The oscillations are sensitive to the electron potential and abruptness of the film and its interfaces. In particular, inelastic scattering and/or thickness inhomogeneities in the film will reduce the amplitude of the oscillations. We are using the amplitude of the oscillations to examine the degree of microroughness at the interface that results from a pre-oxidation high temperature anneal in an inert ambient containing various amounts of H2O. Preliminary AFM imaging has shown correlations supporting our microroughness interpretation of the quantum oscillation amplitudes.

Low temperature nitrogen incorporation method for enhanced electrical properties in hafnia based gate dielectrics

2006 ◽  
Vol 89 (24) ◽  
pp. 242902 ◽  
Author(s):  
K. Ramani ◽  
C. R. Essary ◽  
S. Y. Son ◽  
V. Craciun ◽  
R. K. Singh
Keyword(s):  
Electrical Properties ◽  
Low Temperature ◽  
Gate Dielectrics ◽  
Nitrogen Incorporation ◽  
Incorporation Method

Study of HfAlOx Films Deposited by Layer-by-Layer Growth for CMOS High-k Gate Dielectrics

2003 ◽  
Vol 786 ◽  
Author(s):  
Akira Toriumi ◽  
Toshihide Nabatame ◽  
Tsuyoshi Horikawa
Keyword(s):  
Gate Dielectrics ◽  
Layer Growth ◽  
Atomic Diffusion ◽  
Layer By Layer ◽  
Al Content ◽  
Nitrogen Incorporation ◽  
Layer Deposition ◽  
Superlattice Peak ◽  
High K ◽  
Ternary Metal

ABSTRACTWe have investigated ternary metal oxide films for high-k gate dielectrics by using a layer-by-layer deposition & annealing method so as to keep the dielectric constant of the film high with no crystallization. HfAlOx films have been prepared by alternating deposition of HfO2 and Al2O3 layers, where it is a key for the improvement of the film quality to understand the intermixing process between two layers by thermal treatments. So, we first discuss the atomic diffusion and structural change of the HfO2/Al2O3 “superlattice” film as a function of the annealing temperature by changing the Hf/Al ratio. In a typical case of the film with HfOx/AlOx=3Å/9Å cycle, a clear superlattice peak is observed below 750 °C by XRD. Above 850 °C, a different type of crystalline structure with no superlattice peaks is observed. These results indicate that the intermixing in HfO2/Al2O3 (3Å/9Å) films occurs between 750 and 850 °C. The intermixing onset temperature increases with increasing Al content in Hf/Al ratio.To further increase the crystallization temperature, nitrogen incorporation into the film is considered, and effects of the nitrogen incorporation into HfAlOx films are studied from the structural and electrical viewpoints. The results indicate that there is a tradeoff between crystallization restriction and leakage current degradation for the nitrogen incorporation into HfAlOx films.

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