Expert Details

Expert in Semiconductor Back End of Line Processes, Process and Thin Films Characterization, Film Stresses and Reliability. PVD, ALD, CVD, HiPIMS

Expert ID: 736068 Minnesota, USA

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Back-End-of Line (BEOL) Integration in SRAM, Spin-Torque, Resistive Random Access Memory.
PVD, CVD and ALD thin film deposition. Film micro-structure and properties.
Stress-related problems in BEOL.
DC, RF and HiPIMS sputter deposition. Arc evaporation. Plasma-Surface interactions.
13 years academic experience and 23 years industrial experience: University of Linkoping, Sweden; Seagate, Cypress Semiconductor, Polar Semiconductor
22 US Patents issued.
60 peer-reviewed publications. Over 1200 citations.
Reviewer for Thin Solid Films, Surface and Coatings Technology and Vacuum


Year Degree Subject Institution
Year: 1989 Degree: PhD Subject: Physics Institution: Bulgarian Academiy of Sciences

Work History

Years Employer Title Department
Years: 2019 to Present Employer: Undisclosed Title: Owner Department:
Consulting work using my work experience from Academia and Industry. Responsibility is defined per contract.
Years Employer Title Department
Years: 2009 to 2019 Employer: Polar Semiconductor LLC Title: Principal Engineer Department: Operations
Responsible for definition of equipment and processes for manufacturing of automotive mixed-signal array semiconductor chips (one of world largest suppliers Sanken Electric-Japan). Responsible for training of next generation of engineers on deposition, process and film characterization, qualification thin interconnect films. Configured and added 6 Endura5500 AMAT PVD tools. Throughput optimization. Fleet capacity, Interconnect reliability.
Years Employer Title Department
Years: 2007 to 2008 Employer: Seagate LLC Title: Sr Staff Endineer Department: Advanced Technology Group (VP Pat Ryan)
Expert in development of both Al- and Cu-based interconnect for Spin-Torque Random Access memory (STRAM). Resistive random access memory (RRAM). Define requirements, configuration, supplier of PVD tools used in STRAM and RRAM. Active member of corporate equipment council for Seagate, defining company's metal thin films road map and preferred suppliers. Author and co-author of 18 US patents.
Years Employer Title Department
Years: 1997 to 2007 Employer: Cypress Semiconductor Title: Principal Engineer Department: Rest of Fab Department
Metals thin film deposition; Corporate expert in defining and qualifying Al-Cu interconnects in 8 technology generations (0.5, 0.35, 0.25, 0.22, 0.18, 0.13, 0.09 and 0.065 nm). Expert in hot Al process, PVD liner, barrier films, Titanium Silicide and Cobalt Salicide technology, AMAT Endura. Novellus CVD and ALD thin films in back end of line. Reliability.
Years Employer Title Department
Years: 1991 to 1996 Employer: Linkoping University Title: Forskarassitent (Ass. professor) Department: Physics and Measurement Technology
Project investigator in broad range of activity related to design, characterization and use of ultra-high vacuum deposition systems. Plasma-surface interactions, dual magnetron sputtering, reactive sputter deposition, anisotropy of electron energy distribution function in magnetron discharges, layered structures and superlattices. Elastic CNx thin films, Titanium Nitride, Aluminum Nitride, Vanadium Nitride, Chromium Nitride, Perovskite ceramic thin films. Thought classes for grad students (from University of Linkoping, SECO Tools, and SAAB Military Aircraft companies in Sweden) on Contact Methods for Plasma Diagnostics. Prepared and conducted series of Lab work on the use of the Contact Methods for Plasma Diagnostics.
Years Employer Title Department
Years: 1986 to 1991 Employer: Bulgarian Academy of Sciences Title: Staff Scientist I, II and III Department: Ion Technologies for Deposition of Thin Films
Project investigator, Project "Development of Overcoat for Rigid Magnetic Media (Winchester magnetic discs)". Ion-assisted thin film deposition of diamond-like and graphite-like bi-layer system by using DC magnetron sputtering in various inert gases. Development of model for calculating film deposition rate, and its uniformity accounting for direct and gas-phase scattering collisions. First comprehensive characterization of magnetron plasma. First ever measured and published electron energy distribution function in magnetron sputtering discharges.
Years Employer Title Department
Years: 1994 to 1996 Employer: Laser Technologies Title: Physicist Department: Thin Films
Development of thin film materials with thermo-chromic properties (e.g. V2O5 - Magnelli series) experiencing phase transformations below 100C. Development of real-time monitor of mode spatial composition of output laser beam, 5000W, based on CO2.

Career Accomplishments

Associations / Societies
American Vacuum Society
Professional Appointments
Elected Executive Committee Member 1998-99, Minnesota Chapter of American Vacuum Society
Awards / Recognition
Certificate for Outstanding Contribution in Reviewing (Vacuum and Surface and Coatings Technology)
Publications and Patents Summary
37 articles in the area of thin film sputter deposition, plasma properties, plasma contact methods for diagnostic, chemical vapor deposition
4 Invited Speaker (Sweden, France, USA x 2)
16 Presentations at International Conferences and Symposia; Peer reviewed and published in Proceedings
22 issued US Patents (Cypress Semiconductor and Seagate LLC)

Language Skills

Language Proficiency
English Fluent
Bulgarian Fluent
Russian Fluent

Fields of Expertise

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