Title :
Latent gate oxide defects caused by CDM-ESD
Author :
Reiner, Joachim C.
Author_Institution :
Reliability Lab., Swiss Federal Inst. of Technol., Zurich, Switzerland
Abstract :
This paper investigates the phenomenon of latent gate oxide defects in MOS ICs caused by charge device model ESD (CDM-ESD). It was observed in about 58% of the MOS memory ICs investigated here. A physical model, called the "Melt Ball Model", has been developed to explain the creation of these gate oxide defects. It predicts the formation of a low conductivity and voltage stress sensitive amorphous "filament". The results of a focused ion beam-transmission electron microscopy (FIB-TEM) investigation are presented confirming this model. Further, experimentally observed leakage current instability phenomena connected with the investigated latent defects are described in detail. The dependence of the CDM-ESD damage threshold for the creation of the observed gate oxide defects on the chip layout is described quantitatively for an n-MOS SRAM.
Keywords :
MOS memory circuits; SRAM chips; dielectric thin films; electric breakdown; electrostatic discharge; failure analysis; focused ion beam technology; integrated circuit modelling; integrated circuit reliability; leakage currents; transmission electron microscopy; CDM-ESD damage threshold; FIB-TEM; MOS ICs; MOS memory ICs; NMOS SRAM; charge device model ESD; chip layout; focused ion beam-transmission electron microscopy; latent gate oxide defects; leakage current instability phenomena; melt ball model; n-MOS SRAM; physical model; voltage stress sensitive amorphous filament; Amorphous materials; Conductivity; Electron beams; Electron microscopy; Electrostatic discharge; Leakage current; Low voltage; Random access memory; Stress;
Conference_Titel :
Electrical Overstress/Electrostatic Discharge Symposium Proceedings, 1995
Conference_Location :
Phoenix, AZ, USA
Print_ISBN :
1-878303-59-7
DOI :
10.1109/EOSESD.1995.478299
