Senior Process Engineer, Wet Etch

Job Description

Primary Duties & Responsibilities

• Develop and optimize wet etch processes for VCSELs, photodiodes, and edge-emitting lasers (EMLs) on GaAs and InP substrates.
• Define and control etch chemistry, etch rate, isotropic vs. anisotropic etching, selectivity, and undercut management to meet stringent device performance criteria.
• Utilize metrology tools such as AFM, SEM, ellipsometry, profilometry, XPS, XRD, and optical interferometry for process characterization and defect analysis.
• Troubleshoot etch process deviations, material compatibility issues, and surface roughness effects, implementing corrective actions to ensure high device yield and process stability.
• Work closely with device engineers and integration teams to integrate wet etch processes into the overall semiconductor fabrication flow.
• Establish and maintain Statistical Process Control (SPC) methodologies for process monitoring and continuous improvement.
• Evaluate and qualify new wet etch chemistries, process automation techniques, and etch equipment to enhance process capabilities.
• Develop and document etch process recipes, SOPs, failure analysis reports, and best practices for knowledge sharing and training.
• Mentor junior engineers and provide technical leadership in wet etch process development for optoelectronic applications.
  
  

Education & Experience

• Bachelor’s, Master’s, or Ph.D. in Materials Science, Electrical Engineering, Chemical Engineering, Physics, or a related field.
• 10 years of hands-on experience in semiconductor wet etch process development, particularly for GaAs and InP-based optoelectronic devices.
• Strong expertise in wet etch chemistry, selectivity optimization, surface roughness control, and etch stop layers.
• Hands-on experience with metrology techniques such as SEM, AFM, ellipsometry, profilometry, XPS, and XRD for process verification and defect analysis.
• Deep understanding of etching challenges for VCSELs, photodiodes, and edge-emitting lasers (EMLs), including precise mesa formation, sidewall passivation, and optical performance impact.
• Proficiency in SPC (Statistical Process Control), DOE (Design of Experiments), and data-driven process optimization.
• Ability to work in a cleanroom environment and collaborate with cross-functional teams, including device engineers, production teams, and R&D groups.
  
  

Skills

• Experience in high-volume semiconductor manufacturing or advanced R&D prototyping for optoelectronic devices.
• Familiarity with chemical safety, fume hood operations, and waste disposal protocols for semiconductor wet etch processing.
• Familiarity with automation (SECS/GEM), scripting, or AI-driven process control, including FDC (Fault Detection and Classification) and APC (Advanced Process Control)
• Demonstrated leadership in technical project management, process transfers, and mentoring junior engineers.
  
  

Working Conditions

• Will be exposed to areas where hand tools and power tools are being operated
• Will be exposed to areas where hazardous chemicals or gases are stored
• Ability to work in a cleanroom environment per semi-conductor protocol/requirements
  
  

Physical Requirements

• Work in a class 100/1000 clean room for extended periods
• Wear full cleanroom attire (smock, mask, etc.)
• Work with and/or around chemicals (such as solids and acids)
• Stand for up to 4 hours at a time
• Lift up to 16-30 Pounds
• Push/Pull up to 16-30 pounds
• Sit for up to 4 hours at a time
  
  

Safety Requirements

All employees are required to follow the site EHS procedures and Coherent Corp. Corporate EHS standards.

Quality And Environmental Responsibilities

Depending on location, this position may be responsible for the execution and maintenance of the ISO 9000, 9001, 14001 and/or other applicable standards that may apply to the relevant roles and responsibilities within the Quality Management System and Environmental Management System.

Culture Commitment

Ensure adherence to company’s values (ICARE) in all aspects of your position at Coherent Corp.:

Integrity – Create an Environment of Trust

Collaboration – Innovate Through the Sharing of Ideas

Accountability – Own the Process and the Outcome

Respect – Recognize the Value in Everyone

Enthusiasm – Find a Sense of Purpose in Work

Coherent Corp. is an equal opportunity/affirmative action employer. All qualified applicants will receive consideration for employment without regard to sex, gender identity, sexual orientation, race, color, religion, national origin, disability, protected Veteran status, age, or any other characteristic protected by law.

If you need assistance or an accommodation due to a disability, you may contact us at talentacquisition@coherent.com .

About Us

Coherent is a global leader in lasers, engineered materials and networking components. We are a vertically integrated manufacturing company that develops innovative products for diversified applications in the industrial, optical communications, military, life sciences, semiconductor equipment, and consumer markets. Coherent provides a comprehensive career development platform within an environment that challenges employees to perform at their best, while rewarding excellence and hard-work through a competitive compensation program. It's an exciting opportunity to work for a company that offers stability, longevity and growth. Come Join Us!

Note to recruiters and employment agencies: We will not pay for unsolicited resumes from recruiters and employment agencies unless we have a signed agreement and have required assistance, in writing, for a specific opening.

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