Maintenance Mindset: 6 maintenance musts in semiconductor manufacturing

In the wake of the chip shortage and continued increased demand for semiconductors, fab production rates take center stage. To be the best semiconductor fabrication facility you can be, getting a handle on equipment recovery, planned maintenance, and parts management for fab equipment is just as important as mastering the intricate processes that the equipment performs.

While the Creating Helpful Incentives to Produce Semiconductors (CHIPS) and Science Act has been flowing significant investment and support to new U.S.-based infrastructure, global management consulting firm McKinsey & Company says many current fabs are at least 20 years old, especially facilities that create 200 mm legacy chips for automotive, industrial, and wired communication. Many of the newer facilities and investment are for advanced 300 mm wafers, which make up 60% of the market for computing, data storage, wireless communication, and artificial intelligence (AI).

Not surprisingly, many older fabs are stuck in reactive maintenance mode. The lack of a structured maintenance plan means that maintenance workers are solely focused on fixing what’s broken. In its observations of semiconductor manufacturers, McKinsey found that some fabs perform more unplanned maintenance than scheduled maintenance. Of the fabs that McKinsey has observed and worked with, about 40 to 70% of maintenance time is spent on firefighting or reactive maintenance because a tool is down. (Note: this McKinsey study is focused on the older legacy chip facilities.)

McKinsey predicts that an hour of planned maintenance at a fab can typically save three or four hours of unplanned maintenance. Implementing a planned maintenance schedule for a fab can also be challenging because of the wafer production process. As a wafer moves through the chip-making process, the steps are both complex and interdependent. Stopping one process will stop the entire production line, which can make rooting out the cause of failures (a defective chip or lowered production) more difficult to pinpoint.

Here are six ways planned and preventive maintenance tasks that can make a difference for semiconductor manufacturers:

1. HVAC maintenance—semiconductor fabrication requires a controlled environment, which is maintained by cleanroom facilities that must be regularly inspected. Airflow blockages or temperature fluctuations can alter cleanroom environments without regular maintenance and calibration of the HVAC systems.
2. Equipment efficiency—advanced cooling and lighting systems help semiconductor fabs maintain energy-efficient systems for operational efficiency and reduced energy consumption. Cleaning and servicing these systems extend equipment lifespan and prevents overheating and reduced efficiency.
3. Water purification—fabs need ultrapure water for semiconductor manufacturing (for cleansing, rinsing, and chemical processes), and advanced systems remove impurities. Preventive maintenance for these systems includes regular inspections and replacing the filtration membranes. Regular PMs are necessary to ensure that a compromised filtration system doesn’t introduce impurities into the water supply, which will affect wafer quality and lead to chip defects.
4. Hazardous material maintenance—semiconductor manufacturing does use some hazardous chemicals and gases. Chemical storage and handling systems require regular inspection and maintenance to prevent leaks.
5. Processing tool maintenance—wafer handlers, etching chambers, and deposition systems need scheduled inspections to identify wear, contamination, or deviations. Diagnostic tools like thermal imaging and vibration analysis can be combined with visual inspections.
6. Contaminant removal—A well-defined maintenance schedule is critical for components like vacuum pumps, gas delivery systems, and cooling units. Regular servicing should include cleaning to remove contaminants and make any adjustments needed to maintain performance. The planned maintenance schedule should consider the production cycle to minimize disruptions, as well as ensure peak performance and reduce equipment downtime.

Ever wonder what a day in the life of an equipment maintenance technician would be like? Read part three of this series on semiconductor maintenance manufacturing from Polar Semiconductor.

In many places, open technician positions far outpace available skilled workers. Read part one of this series to learn about manufacturers that are turning to collaborative robot that performs maintenance at fabs.