Method of making an ultra thin dielectric for electronic devices
AssigneeThe Regents of the University of Texas System
InventorsDim-Lee Kwong, Giwan Yoon, Jonghan Kim, Liang-Kai Han, Jiang Yan
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Abstract
High quality, ultra thin (<30 .ANG.) SiO.sub.2 /Si.sub.3 N.sub.4 (ON) dielectric layers have been fabricated by in situ multiprocessing and low pressure rapid-thermal N.sub.2 O-reoxidation (LRTNO) of Si.sub.3 N.sub.4 films. Si.sub.3 N.sub.4 film was deposited on the RTN-treated polysilicon by rapid-thermal chemical vapor deposition (RT-CVD) using SiH.sub.4 and NH.sub.3, followed by in situ low pressure rapid-thermal reoxidation in N.sub.2 O (LRTNO) or in O.sub.2 (LRTO) ambient. Results show that ultra thin (T.sub.ox,eq =.about.29.ANG.) ON stacked film capacitors with LRTNO have excellent electrical properties and reliability.
Claims9
A method of in situ forming a dielectric layer on a silicon surface of a substrate in an electronic device comprising the steps of
- a) exposing said silicon surface to an atmosphere of NH.sub.3 at a first elevated temperature for a first period of time to remove native oxides and form a first Si.sub.3 N.sub.4 layer,
- b) chemical vapor depositing a second Si.sub.3 N.sub.4 layer on said first Si.sub.3 N.sub.4 layer, and
- c) forming an oxynitride layer on said second Si.sub.3 N.sub.4 layer by heating said second Si.sub.3 N.sub.4 layer at a second temperature for a second period of time in an atmosphere of nitrous oxide.
Dependencies are inferred from the claim text.