Rohde & Schwarz

To provide turnkey solutions for semiconductor test, Rohde & Schwarz cooperates with a variety of partners.  In particular, network analyzers from Rohde & Schwarz provide the essential measurement data. Partners have chosen these instruments due to their high accuracy, high speed and reliable performance, all meeting the specifications diligently documented in data sheets.

Wafer level characterization is a critical part of RF and microwave semiconductor design and debug, including modeling modern high-performance semiconductor devices. For on wafer characterization of RF and mmwave components, Rohde & Schwarz collaborates with long-term partner the MPI Corporation in Taiwan, to offer turnkey solutions for measurements on semiconductor components. Rohde & Schwarz contributes network analyzers directly supporting frequencies up to 110 GHz with frequency converters extending the range up to 1,100 GHz, developed to work in conjunction with MPI wafer probers in all-in-one solutions designed for precision analysis of 150 and 200 mm wafers:

• The TS150-THZ is the first 150 mm wafer dedicated probe station on the market designed explicitly for mmwave and THz on wafer measurements.
• The TS200-THZ for 200 mm wafers adds active impedance tuner integration providing accurate tests for the combination of requirements for mmwave, THz, and automated impedance tuner applications (see Figure 3).

For developing active components such as power amplifiers running under compression showing nonlinear behavior such as impedance variance and reflection effects, load pull varies the load impedance at the DUT to determine the optimum matching.  R&S partners Focus Microwaves and Maury Microwave provide packages featuring R&S ZNA, ZNB (see Figure 14), and ZVA network analyzers for load pull measurements from 10 MHz to 110 GHz.

Figure 14. R&S ZNB vector network analyzer.

For modulated tests of semiconductors in 5G or satellite links, according to the target application the wideband vector signal generator R&S SMW200A supports up to 2 GHz of bandwidth and 44 GHz RF frequency, the signal and spectrum analyzer R&S FSW even goes up to 90 GHz with an with an internal demodulation bandwidth of 8.3 GHz due for release in July.

For production and characterization of 5G FR2 RFICs, the radio communication tester R&S CMP200 offers a unique highly integrated solution supporting CW and modulated tests in the FR2 frequency range. The combination with the IF connections enable cost-efficient test of highly integrated RFICs with an IF connection. The compact shielding chamber for OTA test R&S CMQ200 pairs ideally with the communication tester for packaged 5G FR2 RFIC devices, which typically also include a mmWave antenna.

For modulated tests, the internal and fully calibrated demodulation bandwidth of the signal analyzer R&S FSW is unique on the market. Up to 8.3 GHz bandwidth for analyzing wideband radar chips or linearization using wideband DPD algorithms for mmWave power amplifier transistors and integrated ICs.

The new high-end network analyzer R&S ZNA offers high dynamic range ensuring highest measurement speed paired with exceptional repeatability and accuracy. In addition, R&S ZNA – together with its predecessor R&S ZVA – are the only integrated network analyzers offering four independent sources to enable fast and in-depth mixer characterization.

The multiport network analyzer R&S ZNBT with up to 24 ports and frequencies up to 40 GHz is ideal for parallel testing of multiple devices as well as the latest high-integrated ICs such as  multichannel active beamformers for 5G or satellite links, which have typically from 5 to 17 ports. The high integration in the R&S ZNBT platform simplifies the handling and the calibration of the multiport test setup.

Future enhancements include the high-end vector network analyzer platform R&S ZNA increasing its frequency range and adding functions for semiconductor testing needs. The signal and spectrum analyzer FSW internal demodulation bandwidth will increase from 2 to 8.3 GHz for automotive and industrial radar chipsets and beyond 5G research is launching soon.

Roos Instruments

While mmwave has traditionally been considered a niche application that is largely ignored in high volume production, with the advent of automotive radar and now 5G NR, these frequencies are becoming more mainstream. To successfully transition mmwave devices from laboratory bench-top setups into production test requires a holistic test strategy that addresses the added complexity of high volume economics and cost dynamics. With over 15 years of experience working with custom production mmwave applications, Roos has gained valuable insight into the challenges their customers face at these frequencies. This has helped the company develop novel solutions in four key aspects of the test system that determine success at millimeter frequencies: instrumentation, interconnect, interfacing and integration.

Starting with the instrumentation, the key aspect of the Cassini ATE is a modular and configurable instrument architecture. This enables drop-in test set instruments that extend the frequency capability of the standard 20 GHz source and vector measure core with VNA measurement capability and performance comparable to bench instruments (see Figure 15). This provides better device correlation while allowing the test system to be tailored to the frequency or application requirements. The configurable nature of the system architecture provides capital expense control and greater port efficiency while allowing for future frequency and capability expansion well into the 100 GHz range.

Figure 15. Test Set instruments provide drop-in, multiport VNA test port capability for the Cassini ATE System.

Roos has a unique device interconnect solution that is a departure from the traditionally fixed, multi-layer production load boards as it is designed to be a configurable environment that incorporates high-performance mmwave interconnects and components. It is comprised of two separate, interconnected layers: a general-purpose fixture and socket/probe card for specific devices or applications as shown in Figure 16.

Figure 16. Cost Breakdown of a Cassini device Interface for mmwave application.

The fixture provides a configurable environment that extends the test system’s measurement port capability with reusable off-the-shelf relays, switches, microwave cabling and waveguide, within a rugged, RF-shielded enclosure (see Figure 17).

Figure 17. Paralleling microwave and mmwave resources inside the fixture(left). This provides cost effective port expansion to the existing test system architecture for specific applications (right).

This enables a less complex socket/probe card design, that is both better performance at mmwave frequencies (lower losses, less parasitics, and optimized ground plane) and a more cost effective production consumable (see Figure 18).

Figure 18. Cost Breakdown Consumable/Reuse Comparison of a Cassini Device Interface and traditional multi-layer load board for mmwave applications.

The ubiquitous nature of microwave and mmwave interfaces between instruments and the device interface layers belies their critical function in the overall solution. Cassini’s interface provides both a repeatable setup for successful calibrations that translates to accurate and repeatable measurements, while also satisfying production floor requirements of no specialized tooling or operator training for setup and servicing. Roos’ patented blind-mate microwave and waveguide interfaces provide self-alignment and pressure contact compliance without any tooling or manual manipulation. This insures consistent and repeatable setup of the test system and test bench that is suitable for high volume insertions. They have partnered with several leading manufacturers of probe and socket cards such as Cohu, Form Factor and Yokowo to offer interfaces on their products and ease the introduction of mmwave test into production (see Figure 19).

Figure 19. Interspersed 80 GHz waveguide and 40 GHz blind-mate signal interface for use with a FormFactor/Cascade Microtech probe card.

Traditionally, the integration of the test system and device-specific fixturing is left to the customer due to the custom nature of the application. By contrast, Roos provides a complete mmwave production solution in both the instrument system architecture and the software to provide; tester configuration management, dynamic instrument and test system integration, and most importantly, layered vector calibration to de-embed measurement results. Ultimately this is where the production proven instrumentation, Interconnect and Interface experience of Roos Instruments and the Cassini platform pay big dividends in time to market, risk mitigation and cost savings for our customers.

Teradyne

Teradyne has been pretty quiet about its offerings but has 5G test solutions provide customers with an easy upgrade path from traditional sub-6 GHz testing into the mmwave frequency range. This enables customers to re-deploy their UltraFLEX ATE installed based with mmwave test capability.  

For example, Teradyne’s UltraWave-MX44 instrument the UltraWave24 (sub-6 GHz) capability up to 44 GHz to address the 5G-NR standard while maintaining full DIB and docking compatibility with existing sub-6 GHz UltraFLEX ATE testers. The UltraWaveMX44 is a single slot instrument in the UltraFLEX system and acts as an extension to the UltraWave24 RF instrument. It provides dedicated mmWave frequency blind-mate coaxial DIB connections which are designed to withstand the challenges of a production environment while providing the performance to source and measure high quality 44GHz test waveforms to the device.

The UltraWaveMX44 seamlessly integrates into the manufacturing flow by maintaining fully legacy compatibility with existing applications. Existing RF DIBs can continue to be used with a system configured with the UltraWaveMX44 instrument without any system reconfigurations.

There are 32 mmWave ports available on the UltraWaveMX44 making DIB design significantly easier because sensitive signal switching is not required on the DIB. And, the system can be configured with up to 128 mmWave ports which may be required when scaling for high site count multi-site testing.

A patented active thermal control within the instrument guarantees temperature stability to ensure that high-performance specifications are meet in the engineering and production environments. The UltraWaveMX44 features an integrated power detector which provides specification traceability. The instrument’s frequency range covers 6 to 44 GHz. The instrument has 800 MHz bandwidth and can achieve greater than 2 GHz bandwidth through its high-performance path. It supports RF and IF interfaces for both 5G IF transceiver and 5G RF Beamformer device coverage. There is a dedicated low phase noise DUT reference clock operating from 100 MHz to 6 GHz to supply a precision reference clock for devices with integrated PLLs.

Teradyne’s extendable 5G test solutions are used for testing 5G devices in characterization and in mass production at wafer probe, package and OTA module test insertions. Teradyne’s UltraWaveMX44 mmwave test solution provides an easy ATE upgrade path from traditional sub-6 GHz to mmwave testing.  This is a key feature as manufacturers have a large installed base of sub-6 GHz ATE equipment (previously used for 4G) and desire to re-deploy such installed base with mmwave testing capability for 5G.