Josephson Junction Engineer

The engineer fabricates Dolan bridge and Manhattan style shadow evaporated structures using bilayer copolymer and PMMA electron beam resists on high resistivity silicon and sapphire wafers. Conforming to standards established by SEMI and the American Physical Society APS, the engineer performs proximity effect corrections, beam dose array sweeps, and critical dimension metrology to achieve bridge dimensions under fifty nanometers. Following e beam exposure and development, the engineer transfers wafers into an ultra high vacuum thin film cluster tool, performing in situ ion beam pre cleaning, multi angle aluminum electron beam evaporation, and controlled in situ thermal oxidation to grow a sub nanometer aluminum oxide tunnel barrier with sub angstrom precision.

While automated CAD proximity correction software and robotic wafer loaders execute pattern exposures, achieving reproducible room temperature junction resistance across multi qubit wafer runs presents formidable physical challenges. Microscopic resist scumming, thermal drift in electron optical columns, chamber base pressure fluctuations, and minute oxidation partial pressure variations can cause critical current to drift by tens of percent across a wafer. The nanofabrication engineer monitors vacuum load locks, calibrates electron beam stigmation and focus, tunes liftoff sonication chemistry, and conducts automated room temperature four point probe wafer probing to guarantee tight Josephson junction frequency distributions for multi qubit processors.

The shift begins at seven thirty in the morning inside the Class 100 cleanroom gowning room. The engineer puts on cleanroom boots, a full bunny suit, nitrile gloves, and a face hood before passing through the air shower into the e beam lithography suite. Today they are patterning sixty four transmon qubit junctions on a three inch high purity sapphire substrate. They load the cassette into the load lock of the 100kV electron beam lithography system, waiting for the high vacuum chamber to reach ten to the minus eight millibars. Opening the BEAMER layout file, the engineer verifies that the

3D proximity effect correction properly accounts for electron backscattering from the dense surrounding ground plane. They align the electron column on a gold cross fiducial marker, tuning the beam stigmation and aperture alignment until the spot size measures under two nanometers. The automated exposure runs for three hours, delivering twenty thousand microcoulombs per square centimeter across the undercut MMA copolymer and PMMA top layer. In the afternoon, the engineer develops the resist in chilled MIBK and isopropanol, using a nitrogen air knife to dry the wafer without collapsing the fragile.

A Josephson Junction Electron Beam Lithography Nanofabrication Engineer designs, patterns, deposits, oxidizes, and inspects sub micron superconducting Josephson junctions that serve as the fundamental non linear inductive building blocks of superconducting quantum bits, quantum parametrons, and SQUID sensors. Operating inside high class cleanrooms, semiconductor nanotechnology centers, and quantum foundry facilities, the engineer controls ultra high resolution electron beam lithography systems and specialized multi angle physical vapor deposition tools.

Core responsibilities include operate high voltage electron beam lithography systems to pattern sub hundred nanometer josephson junction dolan bridge structures., operational coordination, and ensuring strict adherence to Kenyan statutory frameworks and quality standards.

Key organizations hiring for this role include Konza Technopolis Development Authority, Safaricom Advanced Technologies Division, Kenya Bureau of Standards KEBS Metrology Division, Kenya Electricity Generating Company KenGen, alongside expanding opportunities in Nairobi, Mombasa, Kisumu, and regional infrastructure projects.

Josephson Junction Engineer Specialist, Senior Josephson Junction Engineer, Josephson Junction Engineer Lead, Josephson Junction Engineer Consultant

While automated CAD proximity correction software and robotic wafer loaders execute pattern exposures, achieving reproducible room temperature junction resistance across multi qubit wafer runs presents formidable physical challenges. Microscopic resist scumming, thermal drift in electron optical columns, chamber base pressure fluctuations, and minute oxidation partial pressure variations can cause critical current to drift by tens of percent across a wafer. The nanofabrication engineer monitors vacuum load locks, calibrates electron beam stigmation and focus, tunes liftoff sonication chemistry, and conducts automated room temperature four point probe wafer probing to guarantee tight Josephson junction frequency distributions for multi qubit processors.