Electronic Devices and Semiconductor Manufacturing Commons^™

Fabrication Of Silicon Microneedles For Dermal Interstitial Fluid Extraction In Human Subjects, Caleb A. Berry

Electronic Theses and Dissertations

The goal of this project is to design and develop a fabrication process for silicon microneedle arrays to extract dermal interstitial fluid (ISF) from human skin. ISF is a cell- free, living tissue medium that is known to contain many of the same, clinical biomarkers of general health, stress response and immune status as in blood. However, a significant barrier to adoption of ISF as a diagnostic matrix is the lack of a rapid, minimally invasive method of access and collection for analysis. Microfabricated chips containing arrays of microneedles that can rapidly and painlessly access and collect dermal ISF for …

Influence Of Heat Treatment On The Behaviorof Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova

Euroasian Journal of Semiconductors Science and Engineering

By means of Deep Level Transient Spectroscopy the kinetics of the annealing of the levels of tungsten in silicon during heat treatment in the temperature range 150÷4000С was studied. It was found a non-monotonic change in the concentration of deep levels Ec-0.30 eV and Ec-0.39 eV under isothermal annealing: the concentrations of both levels at short times increase, then the concentration level of Ec-0.30 eV sharply decreases, and the reduction of the concentration of deep level Ec-0.39 eV is much slower.

Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov

Euroasian Journal of Semiconductors Science and Engineering

The processes of defect formation in silicon doped by tin and manganese and their interaction with uncontrolled impurities were studied by infrared spectroscopy.It was found that the presence of impurities of transition and isovalent elements leads to a technological decrease in the concentration of process impurities – oxygen and carbon. It was found that the introduction of manganese in Si leads to a strong decrease in the concentration of interstitial optically active oxygen Noopt: in rapidly cooled samples Si there is a decrease of Noopt by 50% compared to the original Si.

Influence Of Impurities Of Refractory Elements On The Inefficiency Of Charge Transfer In Charged Communication Devices, Abdugafur T. Mamadalimov, Shakhrukh Kh. Daliev

Euroasian Journal of Semiconductors Science and Engineering

The influence of impurities of refractory elements on the inefficiency of charge transfer in charge-coupled devices is investigated. Found that the magnitude of the inefficiency of transfer  directly proportional to the density of surface States and the density of surface States in the CCD registers, with the resulting n losses n ≤ 0.1 depends on the type specially introduced impurities. It is shown that in CCD structures doped with impurities Ti, Zr and Hf relative to the control structures, the charge loss is greater, and in doped with impurities W and Mo, the charge loss is less.

Influence Of Rhodium And Iridium Impurity Atoms On The Capacitive Characteristics Of Si-Siо2 Structures, Khojakbar S. Daliev, Shakhriyor Kh. Yulchiev, Xotamjon J. Mansurov

Euroasian Journal of Semiconductors Science and Engineering

It was found that the doping of the semiconductor substrate with Rh and Ir atoms leads to the increase in the density of surface states at the Si – SiO2 interface. It is determined that the surface states, due to the presence of an impurity Rh and Ir are effective generation centers.

Influence Of Heat Treatment On The Behavior Of Deep Levels In Silicon Doped By Tungsten, Shokhrukh Kh. Daliev, Abdugofur T. Mamadalimov, Sayfullo S. Nasriddinov, Anifa D. Paluanova

Euroasian Journal of Semiconductors Science and Engineering

By means of Deep Level Transient Spectroscopy the kinetics of the annealing of the levels of tungsten in silicon during heat treatment in the temperature range 150÷4000С was studied. It was found a non-monotonic change in the concentration of deep levels Ec-0.30 eV and Ec-0.39 eV under isothermal annealing: the concentrations of both levels at short times increase, then the concentration level of Ec-0.30 eV sharply decreases, and the reduction of the concentration of deep level Ec-0.39 eV is much slower.

Infrared Spectroscopy Of Silicon Doped By Stannum And Manganese, Sharifa B. Utamuradova, Ravshanbek M. Ergashev, Khusniddin J. Matchanov

Euroasian Journal of Semiconductors Science and Engineering

The processes of defect formation in silicon doped by tin and manganese and their interaction with uncontrolled impurities were studied by infrared spectroscopy.It was found that the presence of impurities of transition and isovalent elements leads to a technological decrease in the concentration of process impurities – oxygen and carbon. It was found that the introduction of manganese in Si leads to a strong decrease in the concentration of interstitial optically active oxygen Noopt: in rapidly cooled samples Si there is a decrease of Noopt by 50% compared to the original Si.

Capacitive Spectroscopy Of Defects In Semiconductors, Doped By Atoms Of Gadolinium, Shoakhriyor B. Norkulov, Khodjakbar S. Daliev, Makhmud Sh. Dehkanov, Uktam K. Erugliev

Euroasian Journal of Semiconductors Science and Engineering

The processes of formation of defects in silicon, doped by gadolinium are investigated by the method of DLTS. It is shown that in diffusion the introduction of Gd in the Si leads to the formation of deep levels with ionization energies Ec–0.23 eV, Ec–0.35 eV, Ec–0.41 eV and Ec–0.54 eV and a capture cross section of electrons n: 410-17cm-2, 210-15 cm2, 1.110-16 cm2 and 1.510-15 cm2, respectively, and in samples p-Si found only one level with Ev+0.32 eV.

Characterization Of Flexible Hybrid Electronics Using Stretchable Silver Ink And Ultra-Thin Silicon Die, Joshua A. Ledgerwood

Master's Theses

Flexible Hybrid Electronics (FHEs) offer many advantages to the future of wearable technology. By combining the dynamic performance of conductive inks, and the functionality of ultra-thinned, traditional IC technology, new FHE devices allow for development of applications previously excluded by relying on a specific type of electronics technology.

The characterization and reliability analysis of stretchable conductive inks paired with ultra-thin silicon die in theµm range was conducted. A silver based ink designed to be stretchable was screen printed on a TPU substrate and cured using box oven, conveyor convection oven, and photonic curing processes. Reliability tests were conducted including a …

Reduction In Recombination Current Density In Boron Doped Silicon Using Atomic Hydrogen, Matthew Garett Young

Graduate Theses and Dissertations

The solar industry has grown immensely in recent years and has reached a point where solar energy has now become inexpensive enough that it is starting to emerge as a mainstream electrical generation source. However, recent economic analysis has suggested that for solar to become a truly wide spread source of electricity, the costs still need to plummet by a factor of 8x. This demands new and innovative concepts to help lower such cost. In pursuit of this goal, this dissertation examines the use of atomic hydrogen to lessen the recombination current density in the boron doped region of n-type …

Direct Bandgap Cross-Over Point Of Ge1-YSnY Grown On Si Estimated Through Temperature-Dependent Photoluminescence Studies, Thomas R. Harris, Mee-Yi Ryu, Yung Kee Yeo, Buguo Wang, C. L. Senaratne

Faculty Publications

Epitaxial Ge_1-ySn_y (y = 0%–7.5%) alloys grown on either Si or Ge-buffered Si substrates by chemical vapor deposition were studied as a function of Sn content using temperature-dependent photoluminescence (PL). PL emission peaks from both the direct bandgap (Γ-valley) and the indirect bandgap (L-valley) to the valence band (denoted by E_D and EID, respectively) were clearly observed at 125 and 175 K for most Ge_1-ySn_y samples studied. At 300 K, however, all of the samples exhibited dominant E_D emission with either very weak or no measureable E_ID emission. At 10 K, …

Metal-Assisted Etching Of Silicon Molds For Electroforming, Ralu Divan, Dan Rosenthal '14, Karim Ogando, Leonidas E. Ocola, Daniel Rosenmann, Nicolaie Moldovan

Student Publications & Research

Ordered arrays of high-aspect-ratio micro/nanostructures in semiconductors stirred a huge scientific interest due to their unique one-dimensional physical morphology and the associated electrical, mechanical, chemical, optoelectronic, and thermal properties. Metal-assisted chemical etching enables fabrication of such high aspect ratio Si nanostructures with controlled diameter, shape, length, and packing density, but suffers from structure deformation and shape inconsistency due to uncontrolled migration of noble metal structures during etching. Hereby the authors prove that a Ti adhesion layer helps in stabilizing gold structures, preventing their migration on the wafer surface while not impeding the etching. Based on this finding, the authors demonstrate …

Interfacial And Electrokinetic Characterization Of Ipa Solutions Related To Semiconductor Wafer Drying And Cleaning, Jin-Goo Park, Sang-Ho Lee, Ju-Suk Ryu, Yi-Koan Hong, Tae-Gon Kim, Ahmed A. Busnaina

Jin-Goo Park

In this study, the interfacial and electrokinetic phenomena of mixtures of isopropyl alcohol (IPA) and deionized (DI) water in relation to semiconductor wafer drying is investigated. The dielectric constant of an IPA solution linearly decreased from 78 to 18 with the addition of IPA to DI water. The viscosity of IPA solutions increased as the volume percentage of IPA in DI water increased. The zeta potentials of silica particles and silicon wafers were also measured in IPA solutions. The zeta potential approached neutral values as the volume ratio of IPA in DI water increased. A surface tension decrease from 72 …

Experimental And Numerical Investigation Of Nanoparticle Removal Using Acoustic Streaming And The Effect Of Time, Kaveh Bakhtari, Rasim O. Guldiken, Prashanth Makaram, Ahmed A. Busnaina, Jin-Goo Park

Jin-Goo Park

Theremoval of nanoparticles is becoming increasingly challenging as the minimumlinewidth continues to decrease in semiconductor manufacturing. In this paper,the removal of nanoparticles from flat substrates using acoustic streamingis investigated. Bare silicon wafers and masks with a 4 nmsilicon cap layer are cleaned. The silicon-cap films are usedin extreme ultraviolet masks to protect Mo–Si reflective multilayers. Theremoval of 63 nm polystyrene latex (PSL) particles from these substratesis conducted using single-wafer megasonic cleaning. The results show higherthan 99% removal of PSL nanoparticles. The results also showthat dilute SC1 provides faster removal of particles, which isalso verified by the analytical analysis. Particle removal …

In-Situ Ellipsometry Characterization Of Anodically Grown Silicon Dioxide And Lithium Intercalation Into Silicon, Eric A. Montgomery

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

In this thesis, in-situ ellipsometry and electroanalytical investigations of two electrochemical processes are reported: including the formation of anodically grown silicon dioxide and the intercalation of lithium into silicon. Analysis of the ellipsometry data shows that the anodically grown silicon dioxide layer is uniform and has similar properties as thermally grown silicon dioxide. The lithium-ion intercalation data reveals non-uniform thin film formation, which requires further studies and development of appropriate ellipsometric optical models.

Advisers: Eva Schubert and Mathias Schubert

Direct Measurement Of Graphene Adhesion On Silicon Surface By Intercalation Of Nanoparticles, Zong Zong, Chia-Ling Chen, Mehmet R. Dokmeci, Kai-Tak Wan

Kai-tak Wan

We report a technique to characterize adhesion of monolayered/multilayered graphene sheets on silicon wafer. Nanoparticles trapped at graphene-silicon interface act as point wedges to support axisymmetric blisters. Local adhesion strength is found by measuring the particle height and blister radius using a scanning electron microscope. Adhesion energy of the typical graphene-silicon interface is measured to be 151±28 mJ/m2. The proposed method and our measurements provide insights in fabrication and reliability of microelectromechanical/nanoelectromechanical systems.

Direct Measurement Of Graphene Adhesion On Silicon Surface By Intercalation Of Nanoparticles, Zong Zong, Chia-Ling Chen, Mehmet Dokmeci, Kai-Tak Wan

Mehmet R. Dokmeci

We report a technique to characterize adhesion of monolayered/multilayered graphene sheets on silicon wafer. Nanoparticles trapped at graphene-silicon interface act as point wedges to support axisymmetric blisters. Local adhesion strength is found by measuring the particle height and blister radius using a scanning electron microscope. Adhesion energy of the typical graphene-silicon interface is measured to be 151±28 mJ/m2. The proposed method and our measurements provide insights in fabrication and reliability of microelectromechanical/nanoelectromechanical systems.

Interfacial And Electrokinetic Characterization Of Ipa Solutions Related To Semiconductor Wafer Drying And Cleaning, Jin-Goo Park, Sang-Ho Lee, Ju-Suk Ryu, Yi-Koan Hong, Tae-Gon Kim, Ahmed A. Busnaina

Ahmed A. Busnaina

In this study, the interfacial and electrokinetic phenomena of mixtures of isopropyl alcohol (IPA) and deionized (DI) water in relation to semiconductor wafer drying is investigated. The dielectric constant of an IPA solution linearly decreased from 78 to 18 with the addition of IPA to DI water. The viscosity of IPA solutions increased as the volume percentage of IPA in DI water increased. The zeta potentials of silica particles and silicon wafers were also measured in IPA solutions. The zeta potential approached neutral values as the volume ratio of IPA in DI water increased. A surface tension decrease from 72 …

Experimental And Numerical Investigation Of Nanoparticle Removal Using Acoustic Streaming And The Effect Of Time, Kaveh Bakhtari, Rasim O. Guldiken, Prashanth Makaram, Ahmed A. Busnaina, Jin-Goo Park

Ahmed A. Busnaina

Theremoval of nanoparticles is becoming increasingly challenging as the minimumlinewidth continues to decrease in semiconductor manufacturing. In this paper,the removal of nanoparticles from flat substrates using acoustic streamingis investigated. Bare silicon wafers and masks with a 4 nmsilicon cap layer are cleaned. The silicon-cap films are usedin extreme ultraviolet masks to protect Mo–Si reflective multilayers. Theremoval of 63 nm polystyrene latex (PSL) particles from these substratesis conducted using single-wafer megasonic cleaning. The results show higherthan 99% removal of PSL nanoparticles. The results also showthat dilute SC1 provides faster removal of particles, which isalso verified by the analytical analysis. Particle removal …

Valley Splitting In Si Quantum Dots Embedded In Sige, Srikant Srinivasan

Srikant Srinivasan

We examine energy spectra of Si quantum dots embedded in Si0.75Ge0.25 buffers using atomistic numerical calculations for dimensions relevant to qubit implementations. The valley degeneracy of the lowest orbital state is lifted and valley splitting fluctuates with monolayer frequency as a function of the dot thickness. For dot thicknesses ≤ 6 nm, valley splitting is found to be >150 μeV. Using the unique advantage of atomistic calculations, we analyze the effect of buffer disorder on valley splitting. Disorder in the buffer leads to the suppression of valley splitting by a factor of 2.5; the splitting fluctuates with ≈ 20 μeV …

Investigation Of Nanoporous Thin-Film Alumina Templates, Biswajit Das

Electrical & Computer Engineering Faculty Research

This paper presents the results of a systematic study of the fabrication of thin-film alumina templates on silicon and other substrates. Such templates are of significant interest for the low-cost implementation of semiconductor and metal nanostructure arrays. In addition, thin-film alumina templates on silicon have the potential for nanostructure integration with silicon electronics. Formation of thin-film alumina templates on silicon substrates was investigated under different fabrication conditions, and the dependence of pore morphology and pore formation rate on process parameters was evaluated. In addition, process conditions for improved pore size distribution and periodicity were determined. The template/silicon interface, important for …

Influence Of Copper Doping On The Performance Of Optically Controlled Gaas Switches, St. T. Ko, V. K. Lakdawala, K. H. Schoenbach, M. S. Mazzola

Electrical & Computer Engineering Faculty Publications

The influence of the copper concentration in silicon-doped gallium arsenide on the photoionization and photoquenching of charge carriers was studied both experimentally and theoretically. The studies indicate that the compensation ratio (N_Cu/N_Si) is an important parameter for the GaAs:Si:Cu switch systems with regard to the turn-on and turn-off performance. The optimum copper concentration for the use of GaAs:Si:Cu as an optically controlled closing and opening switch is determined.

Nanosecond Optical Quenching Of Photoconductivity In A Bulk Gaas Switch, M. S. Mazzola, K. H. Schoenbach, V. K. Lakdawala, S. T. Ko

Electrical & Computer Engineering Faculty Publications

Persistent photoconductivity in copper-compensated, silicon-doped semi-insulating gallium arsenide with a time constant as large as 30 µs has been excited by sub-band-gap laser radiation of photon energy greater than 1 eV. This photoconductivity has been quenched on a nanosecond time scale by laser radiation of photon energy less than 1 eV. The proven ability to turn the switch conductance on and off on command, and to scale the switch to high power could make this semiconductor material the basis of an optically controlled pulsed-power closing and opening switch.