Effects of annealing on charge in HfO/sub 2/ gate stacks

Author

Zhang, Z. ; Li, M. ; Campbell, S.A.

Author_Institution

Dept. of Electr. & Comput. Eng., Univ. of Minnesota, Minneapolis, MN, USA

Volume

26

Issue

1

fYear

2005

Firstpage

20

Lastpage

22

Abstract

This letter presents a systematic investigation of charge in HfO/sub 2/ gate stacks. Assuming that the majority of charge is associated with the stack interfaces, it is found that the charge at the HfO/sub 2//interfacial layer (IL) interface is negative while the charge at the Si/IL interface is positive. In general, the calculated charge densities at both interfaces are of order 10/sup 12/ cm/sup -2/. A forming gas anneal (FGA) reduces the interface charge greatly at both interfaces. However, the FGA temperature does not have much effect on the charge density. The effects of post deposition anneal at various temperatures and under various atmospheres are also studied. Its found that a high temperature dilute oxidizing atmosphere anneal reduces the charge at both interfaces.

Keywords

annealing; electrodes; forming processes; hafnium compounds; interface states; silicon; work function; HfO/sub 2/; HfO/sub 2/ gate stacks; Si; Si-IL interface; annealing effects; dilute oxidizing atmosphere; forming gas anneal; interfacial layer interface; metal gate electrode; stack interfaces; work function; Annealing; Atmosphere; Chemical vapor deposition; Chromium; Dielectrics and electrical insulation; Electrodes; Hafnium oxide; Temperature; Voltage; Annealing; charge; gate dielectric; high-; metal gate electrode; work function;

fLanguage

English

Journal_Title

Electron Device Letters, IEEE

Publisher

ieee

ISSN

0741-3106

Type

jour

DOI

10.1109/LED.2004.840016

Filename

1372683