The semiconductor industry strongly relies on its abilityto continuously scale device feature size to increaseperformance and reduce power consumption as well ascost. One of the many challenges in Nonvolatile Memoryscaling is the physical and electrical scaling of the ONOstack, due to the reduction in program and erase voltagewindows. Historically, a capacitor or transistor structureis employed in the electrical characterization of ONOstackes, however these are both costly and timeconsuming processes. A reliable in-line characterizationof ONO films is required for rapid assessment andoptimization of new ONO layer materials such asalternate tunnel oxides or alternate storage node nitrides.This work demonstrates the in-line electricalcharacterization ONO stacks for rapidly assessing theimpact of tunnel oxide variations on ONO stack program /erase performance.The physical and electrical characterization of the ONOwith 4 variations on Tunnel Oxide and 2 variations onNitride will be presented. The physical characterizationincludes film density and thickness by X-ray Reflectivity(XRR). The electrical characterization of Tunnel Oxide“Stress Induced Leakage Current” (SILC) as well as ONOprogram / erase performance is evaluated using theCOCOS non-contact in-line technique on aSemiconductor Diagnostics, Inc (SDI) tool. The physicaland electrical characterization of the Tunnel Oxide,Nitride and full ONO stack combine to insights intotrends and combinations for improved Program / Eraseperformance in the semiconductor device. Thesemiconductor device may be a SONOS two-bitEEPROM device or a floating gate FLASH memorydevice including an ONO structure.
