On-Wafer Characterization of Silicon Transistors Up To 500 GHz and Analysis of Measurement Discontinuities Between the Frequency Bands

Abstract

This paper investigates on-wafer characterization of SiGe HBTs up to 500 GHz. Test structures for on-wafer TRL calibration have been designed and are presented. The TRL calibration method with silicon standards has first been benchmarked through EM-simulation. Passive and active components are then characterized up to 500 GHz. The slight discontinuities between the frequency bands are explored. A specific focus was placed on incorrect horizontal probe positioning as well as on probe deformation, resulting in a better assessment of possible measurement errors.

Importance and Requirement of Frequency Band Specific RF Probes EM Models in Sub-THz and THz Measurements up to 500 GHz

“…5. The intrinsic EM simulation does not show any discontinuity over the entire frequency range and a similar trend is expected if only one probe model is used in the analysis [14]. Using the frequency band specific probe models in the EM simulation, the discontinuity in the measured data is correctly predicted by the EM simulation.…”

“…In the design of a microstrip or co-planar based calibration kit, a thru of length of more than 400 µm to less than 100 µm was used [14], [24]- [28]. The advantage of a microstripbased calibration kit is the elimination of the higher order modes [27].…”

“…In [10], [15], the EM simulation analysis covering more than one frequency band is presented using only one RF probe model. For Si based test structures also, EM simulation analysis covering more than one frequency band (1 GHz to above 110 GHz) is presented using only one RF probe model [13], [14], [17]. In fact, the geometry and layout for each RF probe depends on the frequency band as well as on the probe head supplier.…”

THz Characterization and Modeling of SiGe HBTs: Review (Invited)

“…Above 70 GHz, the characterization of transistors on Siwafers becomes more challenging [6]. Only very few demonstrations of transistor measurements at higher frequencies have been performed on silicon substrates [5], [7]- [10]. Voinigescu et al [8] have demonstrated measurements up to 325 GHz of an advanced SiGe HBT (hetero-junction bipolar transistor) and have shown results of parameters S21 and H21 along with the maximum available gain MAG.…”

Transmission loss of screen-printed metallization at millimeter-wave frequency

“…The mmW frequency is expected to work not only for their available frequency resources, but also for high-speed and large-capacity communications. Although, some devices operating up to 110 GHz have already been commercialized, the use of mmW frequency (>110 GHz) is still in its early stages of development [1,2]. Generally, planar circuits are utilized for integration of circuits in a device.…”