Compensating Probe Misplacements in On-Wafer S-Parameters Measurements

Abstract

As the maximum frequency of electronics is rising, 1 on-wafer measurements play an important role in modeling 2 of integrated devices. Most of the time, due to the lack of 3 measurement accuracy beyond 110 GHz, such models are usually 4 extracted at frequencies much below their working frequencies 5 and are subsequently extrapolated. The validity of such models is 6 then mostly verified after fabrication of the complete chip, with a 7 simple pass and fail test. This is stating the necessity of enhancing 8 measurement results by any means possible, i.e., to reduce the 9 overall uncertainty in such measurements. It is widely accepted 10 that one of the main sources of uncertainty in such measurements 11 is probe contact repeatability, since it is difficult to reach 12 position accuracy below a few micrometers. We are presenting 13 in this article a method to model the S-parameter variation with 14 probe position on the pads, which can then be used to either 15 estimate contact repeatability uncertainty or further enhance 16 measurement results. The approach is validated based on the 17 measurements performed at 500 GHz. 18 Index Terms-Calibration, on-wafer measurements, probe 19 contact repeatability. 20 I. INTRODUCTION 21 O N-WAFER S-parameters' measurements have the advan-22 tage to characterize on-chip devices without the need 23 for complex waveguide packaging in mm and submm-wave 24 frequencies. In addition, it is a key method for modeling such 25 integrated components, allowing for a much closer evaluation 26 of the manufacturing process, thus improving the overall 27 performance of integrated circuits at these frequencies. The 28 main reason is that the calibration plane is defined directly 29 in the substrate transmission lines. Therefore, it is much 30 closer to the integrated components, without the need to use 31 approximate connector deembedding methods.

GRNN-Based Scattering Parameter Modeling Investigation for HBT at Different Temperature

“…S-parameters have been prominent in the microwave RF field since the mid-20th century. In the meanwhile, it is also used in the design, analysis and simulation for RF microwave active or passive devices [7][8][9][10]. In addition, due to the increasing requirements for RF circuit design, the accuracy of the S-parameter model has an increasing impact on the circuit.…”