Measurement based study of microwave double channel pHEMT device

Abstract

ABSTRACT The paper presents the measurement study of a double channel pHEMT device. Its focus is on examining impacts of several parameters including probe pitch size, position and the applied pressure on the measurements. The impact of probe pitch size, position and applying suitable amount of pressure and more pressure than required on the measuring perspective of a double channel pHEMT was investigated. As noted from the collected data, these impacts are most likely related to the stability factor, current gain and maximum available gain of the studied microwave device. The measurement was done using two probes with pitch sizes of 200 µm and 150 µm, and the probes were placed in the middle of the device’s contact pads while exerting appropriate pressure. For double channel pHEMT on wafer, the outcome can be deemed similar for both pitch sizes. On the other hand, the probe with pitch size of 200 µm is utilised for applying more pressure than required where the probe occupied the entire pads of the device and the findings are skewed. Finally, it was found that the RF measurement is frequently affected by these conditions while the DC measurements are unaffected or have a minor effect.