Imec & Cadence tapeout first test chip for 5-nm technologies

October 08, 2015 // By Graham Prophet
Nano-electronics research centre imec (Leuven, Belgium) and Cadence Design Systems, have announced first tapeout of a 5nm test chip using extreme ultraviolet (EUV) as well as 193 immersion (193i) lithography.

Development of EUV technology has been a major programme at imec over several years (using light of sufficiently short wavelength to enable direct imaging of patterns at nanometre dimensions). To produce this test pattern, imec and Cadence say they optimised design rules, libraries and place-and-route technology to obtain optimal power, performance and area (PPA) scaling using Cadence’s Innovus Implementation System. The geometry came from a processor design, although the exercise was – at this stage – concerned with demonstrating that patterns of the appropriate size could be defined to be laid down on silicon. In parallel with EUV effort imec and Cadence taped out designs using Self-Aligned Quadruple Patterning (SAQP) for 193i lithography, where metal pitches were scaled from the nominal 32nm pitch down to 24nm to push the limit of patterning. (Multiple patterning uses interference and diffraction to form images with dimensions smaller than that otherwise possible with light of a given wavelength – in this case, 193 nm. Whereas a conventional pattern mask will produce a ‘fuzzy’ image, multiple patterning ‘back-calculates’ the effect of interference and diffraction to pre-distort the mask image. Combining several such fuzzy images – in this case, four – can produce the required outcome despite the wavelength/dimension disparity.)

The definition of a metal pitch of 24 nm enables what foundries may, depending on the conventions they are following, choose to call “5 nm” technology. This announcement is concerned with the tape-out, that is, demonstrating that the geometric data for such a step can be generated. Vassilios Gerousis, Distinguished Engineer, Cadence and Praveen Raghavan, Principal Engineer, imec, add that, going forward, “There are three options we plan to expose: 1.) SAQP for the lines with 193i for the cuts and via (multi exposure); 2.) SAQP for the lines with EUV for the cuts and via (single exposure); and 3.) EUV for the lines and vias (no cuts needed).”

They note that there are no actual