Ny transistor waferteknologi med potentiale til at udfordre CMOS
Den netop præsenterede Bizen transistor waferteknologi kan i sammenligning med CMOS nedbringe leadtimes, wafer-areal og proceslag, samtidig med hastigheden og gatedensiteten forøges, og effekforbruget reduceres (in english).A UK collaboration between Nottingham-based start-up, Search For The Next (SFN) and Glenrothes-based Semefab may be set to disrupt the semiconductor industry by implementing a fundamental change at transistor level reaching back five decades to the early bipolar IC era before CMOS became mainstream, using a new process called Bizen.
Bizen applies the principles of quantum tunnel mechanics to any computing or power technology. When compared to CMOS, Bizen results in a five -fold lead time reduction - down from 15 weeks to just three weeks. Moreover, the new process achieves a three-fold increase in gate density that produces a matching three-fold reduction in die size. Lastly, Bizen halves the number of process layers required. All this is achieved while equalling or bettering the speed and low power capabilities offered by current CMOS devices.
David Summerland, CEO SFN explains:
- The CMOS processing industry is hitting a brick wall as shrinking geometries bash up against the laws of physics. We went back to the very beginning and found a way to commercialize quantum tunnel mechanics in silicon or wide bandgap device manufacture. The result is 'Bizen' - Bipolar/Zener - which retains the advantages of traditional bipolar processing yet removes the disadvantages by using Zener quantum tunnel mechanics. This results in lower dynamic power, higher speed and higher gate density, halving the number of process layers required, reducing material use by two thirds, and slashing manufacturing time. This allows any fab to become a category killer.
Bipolar technology has traditionally been limited by its requirement for resistors which have the disadvantage of becoming large in size with low power devices. In contrast, a Bizen transistor uses quantum tunnel technology, enabling designers to eliminate the resistor - as with MOS devices - and take advantage of the now-controllable current.
This enables the realization of a very low power circuit in which the transistor is Normally-On but not saturated, and is controlled by an isolated tunnel connection, rather than a direct metal contact to the base well, as used in traditional bipolar transistors.
Therefore, Bizen technology lets designers create a simpler circuit with far fewer layers and increased logic density. For example, the number of layers needed for a Bizen device range from four to eight for devices supporting low to high voltage operation, compared with ten to seventeen for CMOS. The power consumption drops, the size drops and the integration and speed increases, allowing complex devices to be manufactured in the large geometry fabs that exist in the UK.
Since mid-2017, SFN has been in collaboration with Semefab, the well-known, indigenous, privately-owned semiconductor and MEMS fab based in Glenrothes, Scotland, for process development and qualification leading to device production. Semefab's CEO, Allan James comments:
- If Bizen can be adopted by the industry, an important prize given the reduction in die area at a given technology node comparing a Bizen and CMOS logic implementation would be the ability to wind back the Moores' Law clock by 10 years or more and bring many 'previous-generation' wafer fabs back into mainstream manufacture.