Minimal-invasive Near-field Probing for Over-The-Air On-Chip Component Inspection at Millimeter-wave Frequencies

This paper presents the outcome of the MARIE project C05 (trrmarie.de). C05 carries out research on millimeter-wave (mm-wave) antenna systems for MARIE, which were evaluated with our spherical far-field measurement system. Usually, on-wafer probes are involved in such measurements. Compared to the sizes of most devices under test (DUTs), the on-wafer probe is huge, therefore disturbing the DUT’s far-field by shadowing, scattering, and parasitic radiation. In contrast, the near-field of the DUT is less influenced by the on-wafer probe. In this paper, we introduce different near-field probing concepts at mm-wave frequencies using passive or active probe heads, to solve not only the abovementioned issues for Over-The-Air (OTA) inspection of on-chip components, but also being well-suited for material mapping (together with project M03). In both cases, the near-field probing is done as close as possible to the DUT to capture most spatial harmonics, which vanish in the far-field. Thus, the probe shall be minimal-invasive, mitigating standing waves between the DUT and the probe head.