Engineering Commons^™

Experimental Ion Implantation System For Decaborane Ions, Vijay Babaram

Theses

Future generations of Si technology will require ultra shallow junctions (tens of nm) in the drain and source regions of MOS transistors. Fabrication of such shallow p-type junctions requires implantation of boron at ultra low energies (< 1 keV), below the limits of standard ion implantation technology. A proposed solution involves implantation of B₁₀H_x⁺ ions in which boron atoms carry less than 10% of the beam energy.

This thesis is a part of the feasibility study of this new technology. An experimental ion implantation system was designed and built at Ion Beam and Thin Film Lab, NJIT. The system was tested and the mass analyzing magnet was calibrated using argon ions. Decaborane ions, …

Study Of The Effects Of Deuterium Implantation Upon The Performance Of Thin-Oxide Cmos Devices, Sumit Kishore

Theses

The use of ultra thin oxide films in modem semiconductor devices makes them increasingly susceptible to damage due to the hot carrier damage. Deuterium in place of hydrogen was introduced by ion implantation at the silicon oxide-silicon interface during fabrication to satisfy the dangling bonds. Deuterium was implanted at energies of 15, 25 and 35 keV and at a dose of 1x10¹⁴/cm². Some of the wafers were subjected to N₂O annealing following gate oxide growth. It was demonstrated that ion implantation is an effective means of introduction of deuterium. Deuterium implantation brings about a …

Development Of An Ion Source For Implantation Of Decaborane, Ravidath Gurudath

Theses

Future generations of Si technology will require ultra shallow junctions (tens of nm) in the drain and source regions of MOS transistors. Fabrication of such shallow p-type junctions requires implantation of boron at ultra low energies (≡1keV), below the limits of standard ion implantation technology. A proposed solution involves implantation of B₁₀H_X⁺ ions in which boron atoms carry less than 10% of the beam energy. Thus shallow implantation may be possible with standard ion implanters operating at tens of kV.

This thesis is a part of the feasibility study of this novel technology. The ionization of …

Low Pressure Chemical Vapor Deposition (Lpcvd) Of Titanium Nitride : Synthesis And Characterization, Sameer Narsinha Dharmadhikari

Theses

Titanium tetrachioride and ammonia were used as precursors in a Jow pressure chemical vapor deposition process to deposit titanium nitride films on silicon wafers. The process was carried out at temperatures from 450 to 850 C and the activation energy for the reaction was determined. The order of the reaction, with respect to the partial pressures of the reactant gases, was determined by carrying out the reaction at varying partial pressures of the reactant gases. The following rate equation was established for the reaction:

rate = 4.35*10^-5exp(-5150/T)*(P_NH3)^1.37(P_Ticl4)^-0.42

The titanium nitride thin …

Development And Characteristics Of Carbon Nitride Thin Solid Films For Advanced Coating Applications, Muhammad A. Hussain

Theses

Carbon nitride films were synthesized on silicon substrate by reactive magnetron sputtering of graphite target in an environment of Ar and nitrogen gas. The performance of a negative carbon ion source was also investigated to use the source in negative ion-beam-assisted deposition. These films were synthesized at room temperature at a constant pressure of 5 mtorr and at 300 Watts R.17 power, but at different composition of nitrogen in Ar-N₂ gas mixture ranging from 0-53 percent. The films deposited were microscopically smooth, amorphous and their properties found to be varied with nitrogen composition in plasma. The deposition rate was …

Low Pressure Chemical Vapor Deposition Of Boron Nitride Thin Films From Triethylamine Borane Complex And Ammonia, Narahari Ramanuja

Theses

Boron nitride thin films were synthesized on Silicon and quartz substrates by low pressure chemical vapor deposition using triethylamine-borane complex and ammonia as precursors. The films were processed at 550°C, 575°C and 600°C at a constant pressure of 0.05 Torr at different precursor flow rates and flow ratios.

Several analytical methods such as Fourier transform infrared spectroscopy, x- ray photo-electron spectroscopy, ultra-violet/visible spectrophotornetry, ellipsometry, surface profilometry and scanning electron microscopy were used to study the deposited films. The films deposited were uniform, amorphous and the composition of the films varied with deposition temperature and precursor flow ratios. The stresses in …

Synthesis And Characterization Of Lpcvd Sic Films Using Novel Precursors, Mahalingam Bhaskaran

Dissertations

A unique low pressure chemical vapor deposition (LPCVD) process has been developed to synthesize amorphous and crystalline SiC films using environmentally benign chemicals. The interrelationships governing the process variables, compositions and select properties of the resulting films were established. Such films can be used to produce high quality mask membrane for x-ray lithography. These films can also be used in fabricating high power electrical devices, and hetrojunction devices in conjunction with silicon.

Amorphous SiC films were synthesized using a single precursor, ditertiarybutylsilane, at temperatures below 850°C. Compositional analysis performed on these deposits revealed that, in the deposition temperature range of …

Trifluoroiodomethane As An Environmentally Friendly Gas For Water Patterning By Plasma Etching Process, Krit Aryusook

Theses

Trifluoroiodomethane (CF₃I), a non-global warming gas, has been investigated with study as a substitute for typical CFC etchants, such as CF₄ and C₂F₆, used in wafer pattering technology. This investigation was carried out by exposing dielectric films of silicon oxide (SiO₂) and silicon nitride (Si₃N₄) in CF₃I and C₂F₆/O₂ (used as a reference) plasma environments. The etch rate of these films was ascertained as function of applied rf power, etchant gas flow rate, reaction chamber operating pressure, and O_{2 …}

Synthesis And Characterization Of Silicon Dioxide Thin Films By Low Pressure Chemical Vapor Deposition, Sutham Niyomwas

Theses

Ditertiarybutylsilane ( DTBS ) and oxygen have been used as precursors to produce silicon dioxide films by low pressure chemical vapor deposition. These films were synthesized in the temperature range of 600°C to 800°C at constant pressure, and at different gas flow composition. The films were found to be uniform with a composition that varied with deposition temperature and gas flow ratio. The growth rate was found to follow an Arrhenius behavior with an apparent activation energy of 2.62 kcal/mol. The growth rate was seen to increase with higher distance between wafers and to vary as a function of square …

Characterization Of Low Pressure Chemically Vapor Deposited Boron Nitride Films As Low Dielectric Constant Materials, Manish Narayan

Theses

Boron nitride thin films were synthesized on Si and quartz wafers by low pressure chemical vapor deposition using borane triethylamine complex and ammonia as precursors. The films were processed at 400°C, 475°C and 550°C at a constant pressure of 0.5 Torr and at different precursor flow ratios.

The films deposited were uniform, amorphous and the composition of the films varied with deposition temperature and precursor flow ratios. The thickness of the film increased with increasing flow ratio, but, decreased with increasing temperature. The stresses in the film were either mildly tensile or compressive.

The least dielectric constant for the films …

Low Pressure Chemical Vapor Deposition Of Silicon Nitride Films From Tridimethylaminosilane, Xin Lin

Theses

In this study amorphous stoichiometric silicon nitride films were synthesized by low pressure chemical vapor deposition (LPCVD) using tri(dimethylamino) silane (TDMAS) and ammonia (NH₃). The growth kinetics were determined as a function of temperature in the range of 650 - 900 °C, total pressure in the range of 0.15 - 0.60 Torr, and NH₃/TDMAS flow ratio in the range of 0 - 10. At constant condition of pressure (0.5 Torr), TDMSA flow rate (10 sccm) and NH₃ flow rate (100 sccm), the deposition rate of as-deposited silicon nitride films was found to follow an Arrehnius …

Investigation Of Paraelectric Ptl Thin Films Using Reactive Magnetron Sputtering, Hyun Hoo Kim

Dissertations

The study of methods to prepare paraelectric perovskite PLT (Pb_1-xLa_xTi_1-x/4O₃; x=0.28) thin films has been important because thin films of this high dielectric strength material are required to make high density capacitors for dynamic random access memory. In this research, paraelectric PLT thin films were prepared on multi-layer (Pt/Ti/SiO₂/Si) and MgO substrates in a unique way by the reactive magnetron sputtering method using a multi-component metal target. The individual control of each metal area on the sputtering target had considerable influence on the stoichiometry and electrical properties of the thin …

A Novel Beam-Assisted Thickness Measurement Technique For Nanostructures, Luis Manual Casas

Theses

A novel method for measuring thickness of thin films has been developed. This method is straightforward, quickly accomplished, and offers resolution of device layers approaching that given by transmission electron microscopy. Ion beam bombardment of a multi-layer structure forms a crater in which the crater sidewalls are beveled at a very shallow angle, revealing various layers within the sample at a high degree of magnification. Beveled film thicknesses are measured by scanning Auger electron spectroscopy. Depth profilometry is used to measure the shallow beveling angle. Through knowledge of the beveled layer thickness and the bevel angle, actual film thicknesses are …

Fabrication And Characterization Of Wsi2/P-Si And Tasi2/P-Si Devices, Anitha Kodali

Theses

Thin films Silicides of Tungsten and Tantalum have become very important for IC manufacturing. W and TaSi₂ films were deposited on silicon substrates by CVD and Co-sputtering techniques respectively. These films have been characterized using current-voltage technique. The analysis of the obtained experimental measurements has been performed in the light of Schottky-Mott theory. The effects of annealing were studied using Rapid Thermal Processing technique in the temperature range of 500 to 700°C, in nitrogen atmosphere at a constant pressure of 5x10^-6 ton for a duration of 30 seconds.The increase in annealing temperature resulted in the formation of ohmic …

Control Of Stress In Silicon Nitride Thin Films, Ajay Krishnan

Theses

Silicon nitride thin films of varying composition and thickness were deposited on silicon substrates by reactive rf diode sputtering of a silicon target using an argon/nitrogen gas mixture. Film stoichiometry could be controlled by varying the partial pressure of nitrogen, the total sputtering gas pressure and the target rf power. Films with refractive index of 2.01, the value for stoichiometric silicon nitride, could be obtained. Film stress was measured by wafer curvature; refractive index and thickness of deposited films were obtained by ellipsometry and interferometry measurements. The etch rate in buffered HF for films with refractive index 2.05 was 29A/min; …