Development of a First-of-a-kind Risk Based Process Safety Program in the Semiconductor Industry
Parameswara Subramanian
Over the last few decades, the use of most of liquid and gaseous chemistries has increased exponentially in the Semiconductor industry. In the 1980s only 12 elements were commonly used in silicon wafer processing. Today, almost all elements of the periodic table are explored in semiconductor manufacturing except radioactive and the alkali elements. Considering the properties of the chemistries used in the semiconductor industry, minor chemical releases can result in multi-million-dollar disruptions as it is extremely difficult to recover a clean room from contamination. In order to minimize these disruptions and to improve site safety, Micron has always had an Environment, Health and Safety (EHS) team involving Safety and Industrial Hygiene professionals.
However, this team’s focus was primarily on Chemical handling and Control of hazardous Energy rather than on system engineering and design. Micron’s management recognized this gap and understood that the company lacked a system to proactively prevent process safety related issues. As a result, Micron’s management decided to establish a dedicated Process Hazard Analysis (PHA) team that would address the areas not covered by the existing EHS team as necessary for the company to thrive. Micron’s management acknowledged establishing this team as a reasonable business practice and part of a larger awakening around corporate social responsibility and business excellence. The focus of this team was primarily to review the design of new and first-of-a-kind semiconductor tools and facilities equipment and manage hardware and chemistry changes in these systems.
In addition, all legacy systems were also reviewed and upgraded to the new standard. This team is comprised of several chemical engineers and chemists with unique skill sets and expertise ranging from understanding the hazards of air and moisture reactive chemistries, tool and facility design reviews, pollution abatement technologies, chemical compatibilities, and process safety management. Micron has adopted the risk-based process safety (RBPS) approach as outlined by the Center of Chemical Process Safety (CCPS) and has dedicated engineers in PHA and EHS teams focusing on all the RBPS pillars. The use of RBPS program in the Semiconductor Industry was unique at that time.
During the tool facilitation design and development, the focus is primarily on the “Hazard identification and Risk Analysis” pillar where Hazard and Operability studies (HazOps) and What-Ifs are performed on First-Of-A-Kind (FOAK) tool systems. The need for HazOps is determined by an internally developed Hazard Index. Any significant process change that may potentially increase the risk score is captured through Micron’s Change Management Process that initiates a PHA review. These reviews are part of the company’s engineering and construction business process (ECBP) that also includes Facilities engineering design and construction to support the Fab equipment. Due to the efforts of the PHA team, better records of the hardware changes in the tools were maintained, critical documentation needed for facilities design (that were previously not provided by vendors) were requested and reviewed before system install, design reviews were standardized, and all controls sequences were formalized. As a result of these activities, ECBP was refined, and personnel eventually embraced a process safety focused culture. Based on the R&D PHA model, process safety teams were established in each of the Global Micron Front End manufacturing sites following the pattern set forth by the R&D Center at Boise, ID. Processes that were transferred from R&D to manufacturing included a detailed Safety Release Document (SRD) specifying the design details in R&D so that they could be replicated in the manufacturing site accurately.
The journey to build a process safety culture at Micron has taken 10 years where Micron has moved from a reactionary approach towards a proactive approach in managing risk. As a result, Micron team members at all levels are more engaged in process safety related decisions. This program could not have been successful without the full support of Micron’s top management. The general safety culture has significantly matured as measured by various metrics showing increased productivity and efficiency.
In addition, we are currently building a process safety information database with accurate tool records, hazard identification from HazOps and What Ifs, Management of Change, and other RBPS pillars. This information will then be used for identifying deviation trends that may result in a high severity process safety situation. Micron takes to the highest level the need for a comprehensive group of process safety professionals at every site.
The future at Micron with regards to process safety is to develop a world-class leading-edge process safety organization that is model for all semiconductor manufacturers.