AMS

CASE STUDY 1:
DEEP TRENCH APPLICATIONS

INITIAL MEASUREMENTS
ENABLE ADDITIONAL SUCCESSES
As we move down the nodes, structures get smaller, and more of them are packed on the available space on the wafer. This is especially true of the bottle trench, a new capacitance structure commonly found in the DRAM processes at 90 nm and below.

At Qimonda, process engineers familiar with the capabilities of the AMS IR3000 wanted to know whether infrared reflectance would provide effective metrology on the neck depth and bottle depth.

AMS applications engineers defined the measurements, created an analysis, and were able to correlate the model they created with actual scanning electron microscope wafer inspection results. The conclusion was that the IR3000 model would fit very well for the bottle structures which were, most importantly, fabricated relatively early in the 90 nm process.

After the IR3000 tool was placed at Qimonda, AMS applications engineers continued their testing and model fitting to see if there were other applications that might be generated for the benefit of this customer. Here, they discovered that there was also strong infrared reflectance metrology for neck depth, neck area, bottle depth, bottle taper, and bottle area.

Every time AMS discovers model based applications and develops recipes and models, its entire customer set benefits. As AMS believes that additional applications such as the ones discovered for Qimonda will generate its own business in additional sales of tools, Qimonda becomes the beneficiary of the AMS total commitment to its customers’ metrology solutions.

CASE STUDY 2:
DEEP TRENCH APPLICATIONS

PROVIDING USEFUL DATA
Not all measurements provide useful data. Take, for example, the challenge of measuring Recess One and Recess Two areas on straight trench structures in 110 nm fabrication. An infrared reflectometry analysis of the effects of the Recess is extremely difficult to tell apart from the effects of the silicon nitride film. Without the ability to tell the structures apart, most fabs have failed to automate Recess measurements.

However, the metrology data provided by infrared reflectometry is useful to AMS, as it has developed a methodology to take the Recess data, and subtract out the silicon nitride data, which is provided to the fab by a different metrology tool. As long as the secondary tool will export the data, AMS technologists have been able to create precise model fitting for Recess by factoring in the silicon nitride data.

At Winbond, AMS has proposed that the IR3000 be installed to measure Recess One and Recess Two. As a metrology solutions company, AMS can provide the appropriate methodology to have the fab feed the data forward to the AMS tool. Thus, the expensive and time consuming process of measuring the Recess using atomic force microscopes can become a process of the past.

The development of models which have historically not been subject to non-contact, non-destructive automated metrology remains a targeted market of AMS, which is committed to finding ways to help customers increase their yield.

CASE STUDY 3:
SURFACEWAVE™APPLICATIONS

LEARN WHAT HAPPENS WHEN YOU
ASK AMS TO SOLVE YOUR PROBLEMS
The key determinant as to whether a customer has a successful relationship with its metrology solution provider is the ability of the customer to ask for additional applications, or of the metrology provider to offer additional customer service.

When the customer asks its AMS technical team, “Can You Do This?” the answer is a studied analysis of the situation. AMS considers whether or not the application would help the customer’s yield, and also whether the application is broad-based enough to attract other potential customers.

Alternatively, when the AMS technical or support team asks the customer, “What Other Measurement Can We Make That Will Be Helpful To You?” AMS is seeking collaboration from a valued customer to add further value to the relationship, as well as finding new applications to attract other potential customers.

Recently, when AMD asked AMS to increase certain SurfaceWave™ data accuracy by a factor of three or four times, even at the cost of throughput, AMS determined that this revision in functionality would result in much more APC-ready data, which would, for AMD and other fabs, improve yield and wafer quality. The asking of the question put into play an entire review of SurfaceWave™ , its market position, and the technical ability of AMS to create more meaningful applications.

For a true metrology solutions provider, the only issue is the customer and its needs.