Muhammad Ali J.

SiC Epi growth by MOCVDs on 150mm and 200mm SiC substrates. Working on Improvement of Epi by increasing chip yield and better control of thickness and doping. Development of the processes for improved thickness and doping uniformities. SPC, JMP analysis, PFMEA, DFMEA, Process Improvement, Production Environment. Ownership of Epi process and characterizations. Implementing new Methods/approaches in production line after getting them qualified by the QRB. Using FTIR, CnCV, Lasertech, SIMS, and several other characterization tools to evaluate SiC Epi.

P.I. of the project for SiC Epitaxial growth and their optical and Electronic applications. P.I. of the project for high voltage high current Lateral HEMT. Epitaxy of structure on 6" Si, Device fabrication, and measurement. P.I. of the project for single photon counter using InGaN/GaN avalanche photodiode. Mentoring for epitaxy of materials other than III-Nitrides such as SiC, Fluorides, Tellurides, Selenides, and Sulfides etc. Designing MOCVDs gas mixing systems and type of showerhead. Mentoring modeling/simulation engineers to qualify the custom design of CVD tools. Process development for new tools used for new materials. DOE I-Corps Fellow 2023 Preparation of process description for CVD tools. Proposal writing, project report writing, project presentation preparation, customer and market analysis of products.

Lead 4H-SiC Epitaxial Growth P.I. of the projects for the "development of high-voltage/high-current AlGaN/GaN HEMT" which includes but is not limited to; Growth of AlGaN/GaN on 6" Si substrate using MOCVD and its metrology using AFM, XRD, bow measurement, and Hall effect measurements. Fabrication of AlGaN/GaN Lateral HEMT. Electrical characterization of power HEMT. Designing MOCVDs gas mixing systems and type of showerhead. Preparation of scientific description of MOCVD and its design modifications for clients. Mentoring modeling engineers and feedback based on modeling results for MOCVD custom designs and modeling input parameters for recipe tuning for a specific reactor. Have submitted several Proposals to funding agencies such as DOE, NASA, NSF, and DoD under SBIR/STTR program and won some of them.

ICORLAB at Nick Holonyak Micro and Nanotechnology Laboratory Growth and Metrology: I optimized III-V Nitride (Hexagonal and Cubic) growth using CCS Aixtron MOCVD (3x2") at MNTL, UIUC on sapphire and Si (pattern processing as well) substrates. Following the growth, the quality of the materials is validated by conducting SEM, AFM, XRD, Hall effect measurements, PL, and low-temperature PL. Defect analysis such as dislocations/stacking faults/point defects/grain boundaries. I developed the SOPs to conduct maintenance of MOCVD including replacement of MFCs, filters, installation of metal-organic sources, the modification of MOCVD to switch growth from Arsine or phosphine mode to nitride mode of MOCVD reactor. Processing: I worked on the fabrication of Si U-groove which requires the expertise of Oxidation, lithography, metal hard mask evaporation, metal lift-off, Dry etching using ICP-IPE, HF/BOE process, Anisotropic etching of Si using KOH. For nitrides, I did wet etching experience of GaN and AlN and their mechanical breakdown. Mentoring Graduate and Undergraduates. Writing project reports and preparing project progress presentations.

Growth of GaN thin films (u-GaN, n-GaN, p-GaN, and MQWs) on sapphire substrate by commercial MOCVD (showerhead-based Aixtron (19x2")). The evaluation of crystal quality by SEM, TEM, EDX, AFM, XRD (conducting omega-2-theta scan), Cathodoluminescence (CL), PL, temperature dependent PL, time resolved PL, and carrier concentration using hall-effect measurement. Fabrication of nanoporous GaN by EC-etching and the transfer of top layer onto a foreign substrate by selective EC etching. Growth of GaN thin film and nanowires on BeO substrate. Growth of GaN core NWs (c-axial, m-axial, and a-axial) by VLS approach using MOCVD. Growth of GaN shells, MQW shells of InGaN/GaN, and p-GaN shells for optical and energy harvesting applications. Carrier dynamics evaluation by conducting low temperature TRPL measurements. Using FAB for device fabrication (LEDs, photodetectors, and piezoelectric nanogenerators), processing, and packaging. MENTORING GRADUATE STUDENTS.

Supervisor: Prof. Sang-Wan Ryu Innovation and Development 1- Developed the transfer approach of GaN nanowire embedded in PDMS onto a foreign flexible device 2- Developmed the growth recipes of GaN nanowires on sapphire, GaN thin film, Si, SiO2, graphene, BeO, and Cu foil Responsibilities 1- Studied III-V semiconductor thin films and nanowires for optoelectronic devices and piezoelectric applications. 2- Growth of GaN and GaN/InGaN heterostructures by commercial MOCVD (Showerhead based Aixtron CCS-FT (19x2")) 3- Operation and maintenance of Metalorganic Chemical Vapor Deposition (MOCVD) system. 4- Growth of GaN and GaN/InGaN heterostructures by commercial MOCVD (Showerhead based manufactured Aixtron) 5- Optimized the growth of GaN and GaN/InGaN MQW nanowires on Graphene/SiO2, Si, glass, Cu, sapphire, GaN, and BeO substrates using MOCVD (Showerhead based). 6- Analysis of ultrafast carrier dynamics of semipolar InGaN/GaN MQW nanowires. 7- Fabrication of GaN nanowire based LEDs and photo detectors using MOCVD 8- Fabrication of piezoelectric nanogenerators for ambient energy harvesting using GaN nanowires and thin films. 9- Improved optical properties due to suppressed QCSE and piezotronic effect 10- Additionally, hands-on experience of most the clean-room tools including e-beam evaporation, sputter, PECVD, ICP-RIE, RTA, XRD, PL, and FESEM. 11- I do have experience in processing Si to fabricate Si nanowires using metal-assisted chemical etching using lithography, CIP-RIE, metal deposition, and MACE etching.

I worked as TA to help undergraduate students to solve problems related to several courses.

I worked there to conduct the Atomic Force Resiscopy to measure piezoelectric charges from single GaN nanowire grown on Si substrate.

Designed and conducted experiments to grow ZnO (using CVD) and TiO2 (hydrothermal) nanostructures for optical characterizations. I used CVD, hydrothermal, SEM, AFM, UV/Vis spectrophotometer, XRD, box furnace, and FTIR.

Supervisor: Prof. Arshad Saleem Bhatti Growth of ZnS nanostructures using VLS approach by CVD for optical characterizations. I used SEM, AFM, XRD, EDX, low temperature PL, time resolved PL for the characterizations.

Epitaxial Growth of Hexagonal and Cubic III-Nitrides using Aixtron CCS MOCVD

Title of Thesis: Growth and Characterization of GaN-based Nanowires for Optical and Energy Harvesting Applications

Low temperature time resolved photoluminescence using state of the art setup, The BEST in South Korea. Thanks to Prof. Yong-Hoon Cho and Hyun Gyu Song.

2nd Position in Class Title of Thesis: Optical Properties of Ga-doped self catalyzed ZnS Nanostructures using VLS growth approach by CVD

First in Class