LONDON: Baolab Microsystems SL, based in Barcelona, Spain, is a startup company that claims to be a pioneer in making microelectromechancial systems (MEMS) within the back-end-of-line structure of CMOS wafers.

According to the company, while most MEMS make use of the mechanical properties of silicon, Baolab Microsystems produces NanoEMS using the interconnect metal of conventional CMOS processes in order to create a low-cost addition to CMOS with superior potential for integration. 

Baolab Microsystems, founded in July 2003, said it is applying its technology initially to the field of switching for miniature RF relays inside CMOS, thus enabling smaller mobile phones with improved battery life.

The company claims that the process it has developed is easier and quicker – with fewer process steps than the existing MEMS fabrication techniques, which build the MEMS on the surface of the wafer. The in-process method can cut the cost of MEMS by up to two-thirds, Baolab Microsystems explained in a statement.

Typically, MEMS structures are built in a separately optimised process semiconductor process and brought together with CMOS control circuitry as a two-chip solution or as a multi-chip component.

Baolab Microsystems said its NanoEMS technology uses the existing metal layers in a CMOS wafer to form the MEMS structure using standard mask techniques. The inter-metal dielectric (IMD) is then etched away through openings in the passivation layer using hydrogen fluoride vapour (vHF)