Title :
Investigation of tunneling current through thin dielectrics
Author :
Evtukh, A.A. ; Litovchenko, V.G. ; Kizijak, A.Yu.
Author_Institution :
Inst. of Semicond. Phys., Kiev, Ukraine
Abstract :
Currents through SiO2 ultrathin dielectric films are used for storage and erase charge in EEPROM. The influence of different parameters such as substrate doping level and type, oxide thickness and post-metalization treatments are investigated in detail. MOS structures with aluminium and polysilicon gates were used for study. The substrate doping level influences the Fowler-Nordheim current significantly and this influence is decreased with increasing oxide thickness. Annealing in hydrogen and in H2O reduce the Fowler-Nordheim current. The influence of H2O is stronger. In order to explain observed experimental results, the influence of charge at the Si-SiO2 interface and in SiO2 on experimental I(V) characteristics and corresponding Fowler-Nordheim curves of MOS structures was used. The charge at the Si-SiO2 interface and in SiO2 was determined by step-by-step etching of silicon dioxide and measurements of C(V) characteristics. The influence of charge build-up in SiO2 on the I(V) characteristics of the MOS structure is based on the oxide charge induced tunnel transparency modification. The Fowler-Nordheim current in a MOS structure was calculated in Wentzel-Kramers-Brillouin transparency approximations
Keywords :
CMOS memory circuits; EPROM; WKB calculations; annealing; capacitance; dielectric thin films; doping profiles; electric current; integrated circuit interconnections; integrated circuit metallisation; integrated circuit testing; surface treatment; tunnelling; Al-SiO2-Si; C-V characteristics; EEPROM; Fowler-Nordheim current; Fowler-Nordheim curves; H2; H2O; H2O annealing; I-V characteristics; MOS structures; Si; Si-SiO2 interface; Si-SiO2 interface charge; SiO2 charge; SiO2 ultrathin dielectric films; SiO2-Si; Wentzel-Kramers-Brillouin transparency approximations; aluminium gates; charge build-up; erase charge; hydrogen annealing; oxide charge induced tunnel transparency modification; oxide thickness; polysilicon gates; post-metalization treatments; step-by-step etching; storage charge; substrate doping level; substrate type; thin dielectrics; tunneling current; Aluminum; Annealing; Dielectric films; Dielectric substrates; Doping; EPROM; Etching; Hydrogen; Silicon compounds; Tunneling;
Conference_Titel :
Nonvolatile Memory Technology Conference, 1998. 1998 Proceedings. Seventh Biennial IEEE
Conference_Location :
Albuquerque, NM
Print_ISBN :
0-7803-4518-5
DOI :
10.1109/NVMT.1998.723234
