Title :
Arsenic/phosphorus LDD optimization by taking advantage of phosphorus transient enhanced diffusion for high voltage input/output CMOS devices
Author :
Wang, Howard Chih-Hao ; Chih-Chiang Wang ; Diaz, Carlos H. ; Liew, Boon-Khim ; Sun, Jack Yuan-Chen ; Tahui Wang
Author_Institution :
Device Technol. & Modeling Dept., Taiwan Semicond. Manuf. Co., Hsinchu, Taiwan
fDate :
1/1/2002 12:00:00 AM
Abstract :
Optimization of a LDD doping profile to enhance hot carrier resistance in 3.3 V input/output CMOS devices has been performed by utilizing phosphorus transient enhanced diffusion (TED). Hot carrier effects in hybrid arsenic/phosphorus LDD nMOSFET´s with and without TED are characterized comprehensively. Our result shows that the substrate current in a nMOSFET with phosphorus TED can be substantially reduced, as compared to the one without TED. The reason is that the TED effect can yield a more graded n- LDD doping profile and thus a smaller lateral electric field. Further improvement of hot carrier reliability can be achieved by optimizing arsenic implant energy. Secondary ion mass spectrometry analysis for TED effect and two-dimensional (2-D) device simulation for electric field and current flow distributions have been conducted. The phosphorus TED effects on transistor driving current and off-state leakage current are also investigated
Keywords :
MOSFET; diffusion; doping profiles; hot carriers; rapid thermal annealing; secondary ion mass spectra; semiconductor device models; semiconductor device reliability; 3.3 V; HV I/O CMOS devices; LDD doping profile optimization; RTA; SIMS analysis; Si:As,P; current flow distributions; electric field distributions; hot carrier effects; implant energy; nMOSFET; off-state leakage current; process flow; transient enhanced diffusion; transistor driving current; two-dimensional device simulation; Doping profiles; Hot carrier effects; Hot carriers; Implants; MOSFET circuits; Research and development; Semiconductor device manufacture; Substrates; Sun; Voltage;
Journal_Title :
Electron Devices, IEEE Transactions on