Film-Diode (FD) Process is an ACST originally-developed technology platform for fabrication of discrete devices and integrated circuits for mm/Sub-mm-Wave applications. FD-structures are based on a few-micrometer thin transferred membrane substrate, which maintains integrity of all circuit elements. This approach aims at ultimate performance at mm and Sub-mm-waves.
Various circuit architectures can be accommodated by the FD-process, including discrete diodes and various diode arrays, but also passive circuit elements like are capacitors, resistors, and surrounding circuitry.
Recent FD-based developments include state-of-the-art frequency multipliers up to 330GHz, frequency mixers up to 660GHz, RTD-based oscillators up to 1.1THz, and square-low detectors up to 2.5THz.
Photograph of a RTD oscillator fabricated by FD-Process. For improved power-handling capability and DC-power supply the membrane is mounted on a Si-holder. RF-part of the oscillator is free standing in air. The insert shows a magnified view of the RTD integrated with slot-antenna resonator. The oscillator has been operating at 1111GHz.