Lean Manufacturing principles were introduced in an existing Gallium Arsenide IC factory which manufactures state-of-the-art RF products. While the products produced in this factory were of cutting-edge performance and design, much of the equipment and factory procedures were vintage and in some cases outdated. This situation had worked well at modest production volumes; however, ramping to high volume production has proven difficult. After introducing a new production framework based on Lean Manufacturing principles, dramatic improvements have been achieved in all aspects of factory performance. We will describe the implementation strategy, discuss some of the roadblocks that had to be eliminated, and give a summary of the improvements which were achieved.
Lean is a management strategy that focuses the organization on principles of value to the customer, waste elimination, creation of un-interrupted product flow and continuous improvement. Different Lean tools and techniques such as 5S, TPM and balanced work have been successfully implemented in semiconductor factories in the past few years to varying degrees. However semiconductor manufacturing has been historically laden with anti-lean paradigms and practices. The pace of IC innovation has created a practice of re-tooling to solve processing and productivity challenges.
To offset the capital expense, financial calculations encourage overproduction (keep the tools running!) as product is valued as it is being processed. Over the years processing equipment has migrated to single wafer processing, but lot sizes have remained standardized in the belief that greater lot sizes will maximize utilization. Those examples as well as other anti-lean paradigms of semiconductor manufacturing should be examined, challenged, and replaced with newly developed thought patterns that support change and continuous improvement.
Change of Viewpoint
Challenging the conventional industry and internal thought patterns was only one of the challenges we were facing. A successful transformation into a Lean enterprise requires each employee to change his/her viewpoint and practices in this regard. While acknowledging the need for organizational change is often obvious, recognizing the need for personal change is more difficult and can pose a barrier to adopting a Lean production framework.
Figure 1 illustrates the Lean implementation strategy which was developed and communicated to all factory employees. This illustration proved very effective in communicating the roadmap and in addressing those who resisted change as well as those frustrated with the slow pace of change. Chronic issues were addressed early on with visible changes such as stopping wafer starts to control inventory, factory stand-downs to address yield loss, and canceling plans to purchase additional equipment and software in order to focus on existing systems.
Reducing lot sizes from the historic 24 wafer batch to a lot size of 8 wafers proved to have a dramatic impact on both cycle-time and process yield. A Lean Leaders team was formed by identifying change agents within the organization and training them to use lean techniques to solve problems they were already addressing. Lean training took place on the factory floor as improvement activities occurred, rather than in the classroom.
The improvements in factory performance have been dramatic and have accelerated as more employees adapt their work practices. Figure 2 shows the improvement achieved after the first year of implementation. With employee involvement in the identification and execution of improvements, morale has improved as they directly see the results of their work. The implementation efforts are now focused on expanding throughout the supply chain, sustaining the gains which have been made and creating a factory culture of continuous improvement.
AMCG (Aviv Management Consulting Group) is Aviv’s consulting division which servicing the USA and North America markets.
* Douglas Dopp is VP Wafer Fabrication, Anadigics, Inc.
* Adi Moran is VP Operations, AMCG USA, Ltd