Senior Process Engineer
Vietnam
Posted on Jul 3, 2026
Job Summary:
onsemi (Nasdaq: ON) is driving disruptive innovations to help build a better future. With a focus on automotive and industrial end-markets, the company is accelerating change in megatrends such as vehicle electrification and safety, sustainable energy grids, industrial automation, and 5G and cloud infrastructure. With a highly differentiated and innovative product portfolio, onsemi creates intelligent power and sensing technologies that solve the world’s most complex challenges and leads the way in creating a safer, cleaner, and smarter world.
onsemi is hiring a self-directed and self-driven Process Engineer. This is a fast moving and exciting opportunity that will broaden and enhance one skill and challenge the candidate throughout their career. You would be working in the Central Engineering organization (previously named Corporate R&D) and creating next generation of technologies. In addition, you will be supporting the integration of the wafer technologies into the final package and assembly process on a global basis by working with other fabs and our assembly sites and customers around the world. This opportunity is for those who are technically focused and thrive on solving complex challenges as a critical team member in creating the future technology platforms and intellectual property for onsemi.
Test Process Engineer – Job Description
Position Summary
The Test Process Engineer is responsible for developing, optimizing, and sustaining semiconductor test processes to ensure high yield, reliability, and cost-effective production. This role focuses on troubleshooting test-related issues, driving yield improvement, and ensuring robust test coverage across products.
Key Responsibilities
1. Test Process Development & Optimization
- Develop, qualify, and release test processes for new products (NPI to Production transition).
- Define test methodologies, limits, and guard bands based on characterization data.
- Optimize test programs to improve throughput, test time, and cost efficiency.
2. Yield Monitoring & Improvement
- Monitor daily test yield performance and identify yield loss drivers.
- Perform Pareto analysis on failures.
- Drive root cause analysis (RCA) and implement corrective/preventive actions (CAPA).
- Collaborate with cross-functional teams (Assembly, Design, Wafer Fab) to resolve systemic issues.
3. Defect Analysis & Troubleshooting
- Investigate abnormal test trends (e.g., IDSS shifts, leakage, parametric drift).
- Perform correlation studies between wafer sort, final test, and reliability data.
- Support failure analysis (FA) and validate containment actions.
4. Test Program & Equipment Support
- Support test program development and debug on ATE platforms (e.g., Advantest, Teradyne).
- Ensure proper handler/prober interface and test setup optimization.
- Work with equipment engineering to resolve tester hardware issues.
5. Process Control & SPC
- Implement and maintain SPC controls (UCL/LCL, Cpk, Ppk) for critical parameters.
- Track key metrics such as yield, test escapes, retest rate, and DPPM.
- Establish control plans and reaction plans for out-of-control conditions.
6. Continuous Improvement & Cost Reduction
- Drive test cost reduction initiatives (test time, multisite optimization, program efficiency).
- Improve productivity through automation and standardization.
- Lead yield step-up plans following excursions or recovery events.
7. Documentation & Reporting
- Prepare technical reports, yield summaries, and management updates.
- Document test procedures, specifications, and engineering change notices (ECNs).
- Ensure compliance with quality standards (ISO, customer requirements).
Key Performance Indicators (KPIs)
- Test yield vs target (%)
- Test time reduction (%)
- DPPM / test escape rate
- Retest rate / on-hold rate
- SPC stability (Cpk, UCL compliance)
- Cycle time impact (test-related)
onsemi (Nasdaq: ON) is driving disruptive innovations to help build a better future. With a focus on automotive and industrial end-markets, the company is accelerating change in megatrends such as vehicle electrification and safety, sustainable energy grids, industrial automation, and 5G and cloud infrastructure. With a highly differentiated and innovative product portfolio, onsemi creates intelligent power and sensing technologies that solve the world’s most complex challenges and leads the way in creating a safer, cleaner, and smarter world.
More details about our company benefits can be found here:
| We are committed to sourcing, attracting, and hiring high-performance innovators, while providing all candidates a positive recruitment experience that builds our brand as a great place to work. |
Requirements:
Education
- Bachelor’s or Master’s degree in:
- Electrical Engineering
- Electronics Engineering
- Semiconductor Engineering or related field
Experience
- 2–5+ years in semiconductor test/process engineering (or fresh graduates with strong internship exposure).
- Experience in Assembly & Test (back-end) environment preferred.