Self-Aligned LOCOS/Trench (SALOT) combination isolation technology planarized by chemical mechanical polishing

A novel isolation technology of Self-Aligned LOCOS/Trench (SALOT) has been developed for the isolation of deep-sub micron devices. SALOT has the isolation structure of a Poly-Buffered LOCOS (PBL) field oxide and a self-aligned trench at the center of a narrow field region planarized by the Chemical Mechanical Polishing (CMP) process. With SALOT, dishing was effectively suppressed for field regions as wide as 4 mm. Devices with SALOT show excellent isolation characteristics and gate oxide quality, and low leakage currents. SALOT can be scaled down to the 1 Gbit DRAM generation.<>