Abstract: The number of good IC (Integrated Circuit) chips per wafer or time to print a wafer is optimized by examining a number of prospective chip-to-wafer offsets, and, for each offset, a number of prospective arrangements of reticle exposures (shot maps). Integrating such a shot map optimization sub-system with a reticle layout (frame generation) sub-system permits creation of an optimal shot map for an IC chip of known size. These two sub-systems can also be used iteratively to explore a range of possible chip sizes, presenting the results in a simple graphical form. The instant invention integrates shot map optimization, frame generation and chip size optimization/visualization into a single system, providing the chip designer with insight into the impact of chip size on manufacturability.

Abstract: An integrated circuit having PMOS, NMOS and NPN transistors is described for applications in which both digital and analog circuits are required. The integrated circuit is designed to allow standard CMOS cells to be used in the integrated circuit without redesign. A P+ substrate (48) is provided upon which a first P- epitaxy layer (46) is formed. N+ DUF regions (50,52) are provided for the PMOS and NPN transistors, respectively. The base region (68) is formed in an Nwell (58) by implantation and diffusion. Before diffusion, a nitride layer (70) is formed over the base (68) to provided an inert annealing thereof. The base diffusion and collector diffusion occurs before the CMOS channel stop and source/drain diffusions in order to prevent altering diffusion times for the MOS transistors.

Abstract: A trench structure and fabrication technique is disclosed for isolating adjacent circuits in an integrated circuit. A trench (26) is coated with an oxidation barrier (18) of silicon to protect underlying semiconductor regions (34, 36) from crystal faults and dislocations caused by high temperature oxidation. The trench (26) includes a bottom (50) formed of the substrate (10). The trench (26) is filled with a conductive material which is in electrical contact with the substrate (10). A top surface contact electrode (74) is formed over the trench, in contact therewith, thereby also contacting the underlying substrate (10). For very narrow trenches, semiconductor areas (68, 70) are formed adjacent the top of the trench to thereby provide additional contact surface for the electrode (74).