New System Tests 300mm Wafers in 200mm Test Times

Cleveland, Ohio - December 4, 2003 - Keithley Instruments, Inc. (NYSE: KEI) today announced the newest model in its S600 Series family, the S680DC/RF Parametric Test System. The system allows control of 300mm wafer processes in 200mm test times with the new SimulTest™ parallel test software option (patent pending) for measuring up to nine devices simultaneously within a single probe touchdown. Throughput is further enhanced with improved source-measure units (SMUs) that add faster, more flexible digital communications for easier parallel test programming. These SMUs retain the ultra-low current and high power capabilities of earlier units, and measurements correlate with S600 Series testers already in the field. An enhanced AdapTest Software Option adds intelligence to the wafer testing process, allowing the S680DC/RF System to change test plans automatically in real time, based on die-level results. When used with suitable test structures, the system's unique RF test features enable execution of simultaneous independent DC and RF tests up to 40 GHz on separate probes. Its single-wire 300mm SECS/GEM automation is fully compliant with SEMI and GJG factory standards. Its flexible architecture allows seamless integration of the automation capability into each fab's unique operations.

The S680DC/RF System software and hardware enhancements are also available as cost-effective field upgrades to existing S600 Series systems, which continues the platform's industry-leading capital equipment reuse across multiple technology generations. Consequently, the system's extendable platform adapts easily to emerging measurement needs, like those associated with design rule reductions, new processes, new materials, and new devices.

Application Background

Keithley's S600 Series systems are used by semiconductor wafer manufacturers around the world to assure product performance and reliability by measuring critical device parameters throughout their product cycle. They are used in a wide variety of test environments, including process control, process and equipment tuning and optimization, equipment qualification, wafer acceptance testing, and even device modeling and characterization. Nevertheless, industry trends have converged to produce heightened sensitivity to cost of test (COT). These trends include greater IC density, a larger number of ICs on 300mm wafers, a proportional increase in sampling size, and shifts in product mix to new materials and more analog and mixed signal devices that have greater cost/price sensitivity. Increasing test throughput and reducing COT is crucial for improving the profitability of this mix.

S600 Series testers have always combined high throughput with superior measurement integrity and broad testing flexibility. The S680 DC/RF System hardware and software upgrades advance these capabilities with features that further increase measurement speed and decrease COT at a fraction of the cost to purchase a completely new system. These systems continue to drive down the cost of test over time by maximizing equipment and test program reuse as test requirements change and by helping simplify the transition to new materials and devices. A clear upgrade path is already identified for the next two semiconductor technology nodes. Since the S680DC/RF System shares a common software structure with all other S600 Series testers, it also minimizes engineer and operator training when adding new testers.

Product Details

To create the S680DC/RF System, Keithley improved the S600 Series source-measure unit (SMU) with faster, more flexible digital communications to simplify programming for parallel test. The per-pin electronics design of all S600 Series systems enhances measurement sensitivity by minimizing the parasitic capacitance and leakage currents that hamper the performance of competitive testers. Unlike other testers, the S680DC/RF System has identical, high-resolution DC measurement paths for all tester pins (up to 64), so it's the only parametric tester that provides 100aA and 100nV measurement resolution for all device measurements.

The 40GHz test option of the S680DC/RF System allows accurate characterization of equivalent (electrical) thickness of ultra-thin gate dielectrics, revealing structure subtleties that might not have been seen previously. It also provides production s-parameter measurements for process control of high performance BiCMOS processes. By supplying consistently accurate measurements on these and other semiconductor devices, the S680DC/RF System will cut down on rework and re-probes to verify readings - users get the right results the first time and lower test costs.

The upgraded Keithley Test Environment Software, KTE 5.1.0, delivers customer- and field-requested enhancements and improvements added since the last general release of KTE. The KTE core and its many options deliver the highest data integrity with minimum test time, while minimizing misprocessed material. Test results can be easily imported into a variety of popular device modeling packages, such as BSIMPro™, IC-CAP, and UTMOST™. KTE's test setup, execution engine, and data analysis interfaces have consistently proven to be the easiest to use of all parametric test systems.

Test throughput can be further enhanced with the optional KTE AdapTest software module that adds intelligence to the wafer testing process. This module allows the S680DC/RF System to change test plans automatically in real time, based on die-level results, eliminating the measurement of non-critical parameters on good wafers. AdapTest is ideal for handling scenarios like automated first-level process diagnostics when unexpected results are obtained, and for re-measuring a previous known-good site. This option also allows automated electrical verification of good probe-to-pad contact, including probe tip cleaning as needed. The S680DC/RF System delivers a complete operational model that's fully integrated with a fab's overall automation environment, including test recipe version control and automatic fan-out, with ISO-9001 traceability for recipes.

Additional instrument options are available for specific test needs, including remote testhead pre-amps, C-V meters, pulse generators, LCR meters, frequency counters, and spectrum analyzers. This flexibility allows the system to be used for silicon and III-V wafer devices, RF-BiCMOS analog processes, the latest low leakage devices, advanced memory devices, new materials, and testing driven by lower noise margins needed in wireless communication ICs.

About Keithley Instruments

With more than 50 years of measurement expertise, Keithley Instruments has become a world leader in advanced electrical test instruments and systems from DC to RF (radio frequency) for semiconductor, wireless, optoelectronics, and other segments of the worldwide electronics industry. Engineers and scientists rely on Keithley's instrumentation to make even the most demanding electrical measurements with confidence. Keithley technology can be found on production floors of the most advanced electronics manufacturing facilities, in leading development labs, and in research departments of the world's prominent universities and corporate R&D centers.

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