The answer is Baolab Microsystems which has today announced its NanoEMS technology to do just that, construct nanoscale Micro Electro Mechanical Systems (MEMS) within the structure of a CMOS wafer rather than building on the surface like current techniques. This, says Baolab, means that because it uses less process steps but standard high volume CMOS lines, will reduce the manufacturing costs of a MEMS by up to two thirds.
Using the existing metal layers in a CMOS wafer to form the MEMS structure using standard mask techniques, the NanoEMS process etches the Inter Metal Dielectric (IMD) through the pad openings in the passivation layer using vapour HF (vHF). This etching process uses readily available equipment for volume production, taking less than an hour to complete. As only standard CMOS processes are used, NanoEMS MEMS can be directly integrated with active circuitry as required.
Baolab has successfully created MEMS devices using standard 0.18um 8” volume CMOS wafers with four or more metal layers, and has achieved minimum feature sizes down to 200 nanometres. This is an order of magnitude smaller than is currently possible with conventional MEMS devices, bringing the new NanoEMS MEMS into the realm of nanostructures, with the additional benefits of smaller sizes, lower power consumption and faster devices.
"We have solved the challenge of building MEMS in a completely different way" explained Dave Doyle, Baolab’s CEO. "Existing MEMS technologies are slow, expensive and require specialist equipment. They have to be either built on top of the wafer at a post production stage or into a recess in the wafer. By contrast, our new NanoEMS technology enables MEMS to be built using standard CMOS technologies during the normal flow of the CMOS lines".