DocumentCode :
1935803
Title :
Electronic structure and band offsets in high K oxides
Author :
Robertson, John
Author_Institution :
Dept. of Eng., Cambridge Univ., UK
fYear :
2001
fDate :
1-2 Nov. 2001
Firstpage :
76
Lastpage :
77
Abstract :
The decrease of device dimensions has led to the need for alternative, high dielectric constant (K) oxides to replace silicon dioxide as the gate dielectric in CMOS devices. Silicon dioxide layers thinner than 1.6 would have unacceptably high leakage currents due to direct tunnelling. The alternative is to use thicker layers of high K dielectrics, with the same equivalent capacitance or equivalent SiO/sub 2/ thickness, which increases the tunnelling distance and greatly reduces the leakage current. The band offsets have been calculated using the theory of Schottky barriers of semiconductors, treating the oxide as a wide gap semiconductor. The offsets are found by calculating the energy of the so-called charge neutrality level (CNL) of the oxide and aligning it to the CNL of Si. The calculated conduction band offsets are compared to subsequent experimental values.
Keywords :
Schottky barriers; band structure; conduction bands; energy gap; semiconductor-insulator boundaries; wide band gap semiconductors; Al/sub 2/O/sub 3/; CMOS devices; Schottky barriers; Si; SrTiO/sub 3/; Ta/sub 2/O/sub 5/; ZrO/sub 2/; band offsets; charge neutrality level; conduction band offsets; electronic structure; gate dielectric; high K oxides; high dielectric constant oxides; leakage current; tunnelling; wide gap semiconductor; CMOS integrated circuits; Capacitance; Dielectric devices; High K dielectric materials; High-K gate dielectrics; Leakage current; Photonic band gap; Silicon compounds; Stability criteria; Tunneling;
fLanguage :
English
Publisher :
ieee
Conference_Titel :
Gate Insulator, 2001. IWGI 2001. Extended Abstracts of International Workshop on
Conference_Location :
Tokyo, Japan
Print_ISBN :
4-89114-021-6
Type :
conf
DOI :
10.1109/IWGI.2001.967551
Filename :
967551
Link To Document :
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