Electrical and reliability characteristics of ultrathin oxynitride gate dielectric prepared by rapid thermal processing in N/sub 2/O

Abstract

In this paper, we present the physical and electrical characteristics of oxynitride gate dielectric prepared by rapid thermal processing in N2O ambient. Oxidation rate in N2O is highly controllable and lower than that in 0 2 . Compared with conventional rapid thermally grown oxide, the new oxynitride dielectrics show very large charge-to-breakdown, less charge trapping, less interface state generation, and less threshold voltage shift under constant current stress. Excellent diffusion barrier properties to dopant (BF2) was also observed. AES nitrogen depth profile shows nitrogen pile-up at Si/SiO2 interface, which can explain the improved integrity of oxynitride dielectric.

Accurate negative bias temperature instability lifetime prediction based on hole injection

“…The gate insulator materials are thermally oxidized pure SiO 2 and SiON formed by thermally oxidation and N 2 O oxynitridation [34,35]. Their equivalent oxide thicknesses from capacitance-voltage measurement are 2.0 nm.…”

High-density transition layer in oxynitride interfaces on Si(100)

“…1 Recent studies revealed that nitrided gate oxides in N 2 O ambients had suppressed boron penetration, 2-4 in addition to their enhanced electrical reliabilities. 5 This enhances thermal budgets in annealing which is crucial to circuit fabrication processes. While the improved electrical performances have been attributed to reduced trap states near the interfaces by nitrogen incorporation, the retarded boron diffusion has remained to be explained in terms of the structure of oxynitrides.…”

Rapid thermal multiprocessing for a programmable factory for adaptable manufacturing of ICs

“…It is clear from their work that multiple process steps are required to achieve incorporation of nitrogen at the interface. Nitridation in ammonia requires a reoxidation step to remove the H that is incorporated, since H degrades the device [391, [401. References [41] and [42] use an N2O anneal that has no hydrogen, and hence this was selected as a technology for implementing nitridation in the RTM. Figure 13(a) shows a process sequence implemented in the RTM for oxidation in dry 0 2 at 900"C, followed by an anneal in N20 at 1OOO"C. Figure 13(b) shows a constant-current stress test using substrate injection that compares the NzO annealed oxide to a pure oxide, both dielectrics grown 100 A thick.…”