Metrology Sampling Plans Are Key For Device Analytics And Traceability - SemiEngineering

Determining the communal origin shared by different isolated events.

A parent steps connected the brakes, bringing her car to a halt arsenic she drops her kids disconnected for creation lessons. At the time, she doesn’t announcement thing wrong, but erstwhile she takes her car successful for its regular work appointment, the mechanic conducts a diagnostic cheque and discovers that the superior brake strategy connected the car had failed due to the fact that of a faulty braking controller without anyone realizing it. Fortunately, the car was capable to halt successfully owed to the vehicle’s strategy redundancies, and the dealer’s diagnostic trial confirms that since that archetypal spot failure, different 1 has not occurred. The braking systems are behaving normally.

Following that, the dealership sends the accusation astir the braking nonaccomplishment to the manufacturer, wherever an expert notes that implicit the past 60 days, and astir the country, six different brake failures traced backmost to the aforesaid controller strategy person been reported for the aforesaid marque and model. In each of these situations, the backup strategy successfully brought each car to a implicit stop. And, arsenic successful the lawsuit with the parent who dropped her kids disconnected astatine creation class, the expert looks astatine the reporting samples for these six different failures and determines that each is isolated and non-recurring.

So, what happened, and what whitethorn beryllium the communal origin shared by these different isolated events?

To find those answers, the shaper begins executing a nonaccomplishment mode and effects investigation (FMEA) connected the braking systems for the peculiar marque and model, and they bash so, successful part, by utilizing analytical bundle with genealogy and traceability capabilities. Depending connected the findings, the shaper volition find whether a wide callback is necessary.

After a thorough analysis, the shaper identifies that the faulty chips came from the aforesaid supplier. In addition, the chips are from a azygous transportation the institution had received from the strategy parts provider. Once the parts supplier is notified of this, they behaviour their ain investigation and find that aggregate elements successful the six braking systems were made astatine astir the aforesaid clip successful the aforesaid semiconductor mill overseas and that the chips successful each of the six appeared to beryllium bully erstwhile initially inspected. In fact, the show and electrical results of the atrocious chips met specifications and were wrong expected distributions.

The mill is approached to find if determination are immoderate antithetic signals surrounding the materials utilized successful the operation of the faulty braking systems. Beyond the mean 100% validations checks, outgoing ocular QA, and electrical trial operation wafer acceptance tests (WAT), nary different in-line information is straight recorded connected this material. In this case, this is wherever the investigation stops owed to a deficiency of nonstop information astir the operation of the faulty chips. But it doesn’t close the problem.

Beyond the electrical show characteristics of the parts successful question, semiconductor factories bash not mostly seizure capable oregon typical in-line metrology information for each the parts they manufacture successful their facilities.

In today’s fab environments, executing part-level analytics connected a process-by-process ground is intolerable fixed the astir communal measurement sampling strategies, strategies that person been configured for process power and process sustaining purposes (figure 1). These monitoring and power strategies are woefully inadequate erstwhile applied to merchandise analytics for parts-per-million traceability. Even with bully information extrapolation and enlargement packages, the mistake bars connected immoderate typical information created by these approaches would make results that are insufficient to gully conclusions. To enactment a finer constituent connected wherefore information extrapolation does not work, see the aggregate sources of mistake that people hap successful manufacturing. Extrapolated programs indispensable relationship for measurement instrumentality saltation (gage repeatability and reproducibility) and movie saltation crossed the wafer, the lot, batch to lot, and instrumentality to tool. Accounting for these errors from a applicable standpoint means immoderate extrapolated worth could person mistake bars consuming implicit 50% of the allowed process saltation window.

Fig. 1: A high-reliability strategy requires cognition of wherever each and each constituent originated. Easily accessed genealogy is simply a prerequisite.

While the archetypal investigative lawsuit depicted supra is fictious, the outlined attack to isolating the occupation is simply a apt scenario, arsenic is the deficiency of indispensable information to implicit the broad diagnostics. Moving forward, manufacturers, particularly those providing parts for the automotive and aesculapian industries, volition person a choice. Collectively, they tin determine to proceed to plan solutions with inherent redundancies and make ever much restrictive guard-banding and portion mean trial (PAT) systems to destruct questionable parts and mitigate failures erstwhile they hap successful the field. Or they tin summation the frequence they execute metrology successful their manufacturing operations successful bid to guarantee they person a capable magnitude of information for each azygous portion produced astatine their factories. In this situation, gone would beryllium the days wherever sampling 13 points connected a wafer, 2 wafers successful a lot, and 1 batch retired of 20 would beryllium sufficient.

Today’s manufacturers request to make metrology sampling plans for instrumentality analytics, making this information disposable and traceable to downstream constituent manufacturers and customer-facing strategy providers. Furthermore, linking these much broad metrology sum plans to the disposable responsibility detection and classification (FDC) software results from process tools, on with attraction records and process root chemicals and gasses (GAC), volition yet supply the diagnostic analysts with a implicit and actionable FMEA.

At the extremity of the day, it volition beryllium the extremity lawsuit who drives the champion solution.