Abstracts Book - IMRC 2018

• SA4-P015
CONFORMAL DEPOSITION OF SILICON OXIDE ON Si PLATEAUS BY
TEOS-LPCVD
Maria de Los Angeles de la Cruz García 1 , Enrique Quiroga González 2 , Estela Gomez Barojas 1
1 Benemerita Universidad Autonoma de Puebla, Dispositivos semiconductores, Mexico.
2
Benemerita Universidad Autonoma de Puebla, Instituto de Física, Mexico.
The step coverage of dielectrics is important for the microelectronics industry,
especially for the production of 3D circuits or structures. Very often the goal is
to provide highly conformable films; for example, if the goal is the fabrication of
3D MOS structures, where the dielectric must conformably cover a structured Si
substrate. A common process that allows this feature is the chemical vapor
deposition at low pressure (LPCVD). The precursor materials commonly used for
oxide fillings in LPCVD have been SiH4 and Si2H6, which are toxic and highly
flammable gases. A safer alternative is the use of Tetraethylorthosilicate (TEOS
- Si(OC2H5)4). Although this is an important feature of TEOS as precursor, its most
important attribute is the higher probability to obtain conformal films than with
the standard gas Si precursors. Nevertheless, these last features have not been
exploited for the deposition of Si oxides in commercial devices. In particular,
TEOS has not been tested for deposition on three-dimensional structures such
as plateaus. In this work, an LPCVD system with planar deposition chamber
(allowing laminar flow) and with an evaporator of TEOS, is used for the
deposition of the films. The deposition was performed at 650 o C and pressure
ranging 75 to 300 mbar. The homogeneity and low roughness of the films is
confirmed by AFM and ellipsometry, characteristics that are important for
conformal deposition.
Acknowledgment:
This work has been partially supported by Benémerita Universidad Autónoma
de Puebla through the VIEP-Project: GOBE-EXC18-G, and through the CONACyT
project CB-2014-01-243407. M. A. De la Cruz-García thanks CONACYT for a
graduate student scholarship.
Keywords: TEOS, conformal deposition, LPCVD system
Presenting authors email: a.delacruzgarcia.3@gmail.com