Yield Systems Incorporated

Presents

Integrated Yield Management Methods

Integrated Yield Management Methods ( IYMM ) is a set of strategic methodologies and practices utilized by world-class high-technology companies to increase profits by maximizing yields and productivity . IYMM uses a systematic, interactive approach which makes the best use of existing people, equipment, and resources for rapid and sustained yield and productivity improvements, without major capital investment .

Yield Systems Incorporated ( YSI ) was founded by Mel Effron to provide IYMM consulting services to a world wide client base . Hundreds of engineers have been trained in the IYMM Workshops hosted at the client's location and in seminars over the last 20 years . The IYMM methodologies have been continually upgraded and integrated to include applications consistent with new software, measurement and metrology instrumentation . YSI can provide both training and long term consulting services for the successful implementation of the Integrated Yield Management Methods

Principles

IYMM is a systematic, sequential, 6-level process for increasing and maximizing yield . It incorporates concepts and techniques developed and proven over many years in the semiconductor industry most of which are completely transferable to any complex manufacturing activity .

A cornerstone and foundation of the Integrated Yield Management Methods is the Yield Enhancement Analysis (YEA), a systematic method for quantifying 100% of all the yield losses in the common cause part of the yield population . YEA identifies the process owners for all yield losses, and then sets individual working yield targets and yield learning plans for them . Process owners are given performance plans and objectives based on “Limited Yield” targets and yield modeling projections .

Establishing limited yields for defect types by operations is a necessary part of yield partitioning . The limited yield for an operation is the yield that the final product would have if all other losses were eliminated . Therefore, limited yield is a more effective indicator of actual realizable yield improvements . Measuring limited yields allows each owner to track progress in their area of ownership . Each owner develops yield learning plans and actions to improve the limited yields in their area of ownership . Goal setting for yield improvement is achieved in this manner . Experience has shown that goals set by owners are usually met .

The YEA process represents the long loop for controlling the process, since it requires the product to be completed and tested before yield losses can be discovered, quantified, analyzed and fixed . Efficient manufacturing and rapid learning requires short loops or in-line controls to quickly detect and fix occurring yield problems . The short loop controls are statistically correlated to expected long loop results for accelerated yield learning . Defect measurement equipment, process and equipment control monitors, metrology measurements, and any type of measurement which could be indicative of quality or yield results are all included in the short loop concept . Correlation's can then be developed from the short loop controls to yields, functional parameters and other long loop or final test results . Computer Integrated Manufacturing systems tie data together from all sources and provide real-time information on the health of the manufacturing enterprise .

The IYMM methodology introduces a new degree of discipline to the yield learning process . Discipline is reinforced by a series of specially structured weekly Yield meetings between management and the engineering and production owners . Typically the yield engineers review the weekly YEA data, short loop predictions and progress toward the yield goals as well as any new problems . Actions to address problems and the yield learning plan are presented by the process and equipment owners .

The IYMM methodology is applicable to cycle time and equipment productivity improvement . To improve cycle time the absolute minimum or raw cycle time is determined, losses are quantified and partitioned, owners are defined, goals established and in-line controls put in place . Equipment productivity improvements are driven through the use of well know methods like OEE (Overall Equipment Effectiveness) metric and TPM (Total Productive Maintenance) methodology .

Benefits

The Return on Investment resulting from using IYMM is very quantifiable, since all losses are important . For example, each percent of yield gain for a $200M business running at 80% yield is worth $2 . 5M per year to the bottom line, if fixed . IYMM has had a tremendous impact on client's ability to quantify and control their yield losses, and to obtain maximum benefits quickly .

Products and Services

YSI uses a three step approach for our clients:

Integrated Yield Management Methods - Assessment and Training
On-site Engagement Managers for long term implementation of IYMM
Training and Special Skills to address specific chronic yield or systematic problems .

IYMM Assessment and Training: This is typically delivered through a 5 day, 1 week, intensive program . The core IYM Assessment and Training week consists of two days of intensive class room training including evening homework . Another two days are devoted to a series of interviews with designated groups or individuals from engineering, operations, and management along with a manufacturing line tour . The last day includes an Executive management summary, a discussion of the entire week including the interviews, and presentation of the initial IYMM Project Plan . At the end of the week, the Workshop attendees should have enough "know how" to begin building their own IYMM project plans . The Workshop provides interactive discussions on how to apply the program to whatever resources the client wishes to provide . Many of the methods of IYMM are procedural and cultural in nature, providing very cost effective leverage for immediate pay back . However, senior management's support and participation in the program is crucial to its internalization and success .

The Engagement Manager : Based upon many engagements, we have found the client usually requests that an YSI Associate assist with the development and execution of a long term plan generated in the one Week Assessment . The time frame and frequency of support is usually 6 months to a year, to provide continued focus on the recommendations that come out of the IYMM workshop . The Engagement Manager, along with the client's team, will put together a project implementation plan . He will engage and continually encourage the initial plans on a periodic basis, e . g . 3 days per month . YSI has had many successful engagements based upon this model .

Special skills: Refer to YSI's highly skilled and experienced technical specialists that are available to provide expert resources to quickly address client's unique yield and productivity problems . The range of technical expertise includes: data collection, integration and analysis; yield management practices and yield optimization, critical area modeling and defect density calculations (as appropriate), factory and process cost modeling, and process control, and market and customer driven product and yield requirements .

Regardless of the needs, YSI will work with the client to develop and customize a program tailored to their specific needs .