Increased RF-Losses at the GaN/Si Interface after Eutectic Die Attach
| Autor: | John Twynam, Korbinian Reiser, Robert Weigel, Helmut Brech, Shyam Hardikar |
|---|---|
| Rok vydání: | 2019 |
| Předmět: |
business.product_category
Materials science Silicon business.industry 020208 electrical & electronic engineering Transistor Load pull chemistry.chemical_element 020206 networking & telecommunications Gallium nitride 02 engineering and technology Substrate (electronics) Capacitance law.invention chemistry.chemical_compound chemistry law 0202 electrical engineering electronic engineering information engineering Die (manufacturing) Optoelectronics business Eutectic system |
| Zdroj: | 2019 14th European Microwave Integrated Circuits Conference (EuMIC). |
| DOI: | 10.23919/eumic.2019.8909678 |
| Popis: | The influence of eutectic die attach on RF-substrate losses of AlGaN/GaN HEMTs grown on high-resistivity silicon substrates has been studied. A severe degradation in load pull efficiency is observed after die attach. Analyzing this degradation for dies attached to flanges with differing thermal expansion coefficient shows a linear relationship between substrate strain and load pull efficiency. Loss measurements of coplanar waveguides (CPWs) show increasing substrate losses with increasing strain, while the transistor on-resistance remains unaffected. The degradation in load pull efficiency is, therefore, attributed to increased substrate losses. By evaluating the bias dependence of low frequency capacitance measurements together with the bias dependence of CPW characteristics, we show that the increase in substrate loss can be explained by the formation of interface charge at the GaN/Si interface. To the best of our knowledge, this is the first time that GaN transistor efficiency degradation has been shown to correlate with transmission line losses and changes at the GaN/Si interface after eutectic die attach. |
| Databáze: | OpenAIRE |
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