Sandwich approach could meet future processing requirements
1 min read
Researchers from Ferdinand-Braun-Institut (FBH) and IHP–Leibniz-Institut für innovative Mikroelektronik in Frankfurt have integrated InP and cmos circuits on a silicon wafer. The development is said to support THz capable devices.
According to the researchers, if frequencies beyond 100GHz are to be realised, the breakdown voltage of cmos circuits also needs to be addressed.
By combining a standard cmos circuit with a second InP circuit and sandwiching them on top of each other, the combination is said to deliver high output power at high frequencies.
"It was particularly challenging to make both technologies compatible at the interfaces", said FBH researcher Wolfgang Heinrich. To achieve this, both layers had to be dimensioned so they produced the required transmission properties for frequencies around 200GHz. Precision work was also highly demanded to adjust the circuits precisely to each other with an accuracy of less than 10µm.
Heinrich added: "We managed to align both technology worlds so smoothly that the circuits deliver fully the specified high frequency performance."
The next steps are to improve the process stability and to optimise the circuits.
