​​Photo Engineer – Lithography & Mask Layout​

Location: ​Alhambra, CA​ (Onsite)

Position Summary: The Photo Engineer – Lithography & Mask Layout position is a technical ownership role within an Indium Phosphide (InP) wafer fabrication facility supporting the manufacturing of DFB lasers, Semiconductor Optical Amplifiers (SOAs), and Gain Chip (GC) products. This role is responsible for end-to-end photolithography process development and manufacturing support, including full ownership of mask and reticle layout strategy, stepper and coat/develop track processes, and critical dimension (CD) and overlay control.  The position serves as the primary lithography technical authority for InP device manufacturing, ensuring robust, repeatable, and high-yield lithography processes from tape-out through production. The role requires hands-on expertise in photolithography equipment, layout data preparation, process control, and yield improvement in a compound semiconductor wafer fab environment. 

Responsibilities:  

Photolithography Process Ownership and Manufacturing Support (35%): 

• Own end-to-end photolithography processes for InP-based wafer fabrication, including DFB lasers, SOAs, and gain chip products 

• Develop, qualify, and maintain photoresist, exposure, develop, and post-lithography processes for front-end and back-end layers 

• Provide day-to-day manufacturing support, troubleshooting lithography-related issues and responding to process excursions 

• Support new product introduction (NPI), process transfers, and technology changes within the InP wafer fab 

Mask and Reticle Layout Ownership (25%): 

• Lead mask and reticle layout design for all lithography layers, including: 

• Layer definition, tone selection, and biasing strategy 

• Alignment mark strategy and overlay scheme definition 

• Reticle floor planning and field layout considerations 

• Serve as the primary technical owner for mask/reticle tape-out, review, release, and revision control 

• Coordinate directly with design teams and mask vendors on layout rules, data preparation (GDS, layer mapping), and mask re-manufacture activities 

• Ensure layout-for-manufacturability and lithography robustness across all device layers 

Lithography Equipment and Process Control Ownership (20%): 

• Own stepper and coat/develop track tools, including process qualification, recipe management, and performance monitoring 

• Define and maintain process control monitors (PCM/TCM) to ensure lithography process stability 

• Drive CD and overlay performance through SPC, process window characterization, and data-driven root-cause analysis 

• Partner with metrology and yield teams to improve lithography capability and reduce variability 

Yield Improvement and Defect Reduction (10%): 

• Lead lithography-related yield improvement initiatives and defect reduction efforts 

• Analyze lithography-related yield loss mechanisms and implement cor