A standard cell library for VTT's 0.8µm BiCMOS process

Abstract

AB3:Solukirjasto käsittää sekä CMOS- että BiCMOS-digitaalisolut sekä valikoimananalogiasoluja. -Työssä käsitellään kirjaston yhteenkokoaminen, analogiasolujen suunnitteluja evaluointi sekä osin digitaalisolujen evaluointi.

Digital VHDL synthesis (Very high scale integrated circuits Hardware Description Language synthesis) has achieved a key position in the design of large digital circuits. Since most semiconductor manufacturers have their own standard cell libraries, it was natural for VTT Electronics to develop its own standard cell library for its 0.8µm BiCMOS process. There have also been attempts over many years to develop an analog VHDL synthesis for which a special analog standard cell library would be needed. -The objective of my Master of Science thesis was to collate a standard cell library for VTT's 0.8µm BiCMOS process. It should consist of both analog and digital standard cells. Digital cells or basic digital gates could be through team work. The goal is to have a sufficient number of basic digital gates to allow digital VHDL synthesis to be carried out on these digital standard cells and with VTT's 0.8µm BiCMOS process. My task was to design an analog standard cell library and finally to collate the whole standard cell library for VTT's 0.8µm BiCMOS process. -The digital gates or standard digital cells were mainly done as a team work, with some designers of the IC group making the schematics, some the layouts from those schematics and finally a few person measured the standard digital cells. As a result, the digital standard cell library now contains enough digital cells to run VHDL synthesis properly in VTT's 0.8µm BiCMOS process. -Basic analog circuits were chosen for analog standard cells. They consist of the following circuits: voltage references, comparators, current mirrors, current references, drivers, operational amplifiers and oscillators. The analog standard cell library contains circuits for voltage supplies of both 5V and 3.3V. In addition, there are often circuits for both high-speed and low-power applications in the analog standard cell library. -The design of analog cells started from transistor level. When the specifications had been defined, the layout of circuit was made. After LVS checking (layout versus schematic checking) of one circuit, the circuit was ready for the next MPC run (Multi-Project Chip run). In this way, all the analog standard cells were produced, measured and finally analysed compared to simulation results. Following this procedure, there are now 13 CMOS and 12 BiCMOS analog standard cells in the analog standard cell library. -Finally, the standard cell library contains 21 pure CMOS digital standard cells, 29 high speed BiCMOS digital standard cells, including 13 CMOS analog standard cells and 12 BiCMOS analog standard cells. Altogether, there are 75 standard cells in the standard cell library for VTT's 0.8µm BiCMOS process.