Coating processes – Coating by vapor – gas – or smoke – Mixture of vapors or gases utilized
Reexamination Certificate
2001-12-28
2004-03-30
Meeks, Timothy (Department: 1762)
Coating processes
Coating by vapor, gas, or smoke
Mixture of vapors or gases utilized
C427S255393, C427S255394
Reexamination Certificate
active
06713127
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to the field of semiconductor integrated circuit manufacturing and more specifically to medium temperature deposition and high temperature deposition of silicon oxide films and methods of fabrication of these oxide films.
2. Discussion of Related Art
Chemical vapor deposited (CVD) SiO
2
films and their binary and ternary silicates (generally referred to as oxide films) have wide use in fabrication of integrated circuits such as microprocessors and memories. These films are used as insulation between polysilicon and metal layers, between metal layers in multilevel metal systems, as diffusion sources, as diffusion and implantation masks, as spacers, and as final passivation layers. Acceptable deposited oxide film processes provide uniform thickness and composition, low particulate and chemical contamination, good adhesion to the substrate, and high throughput for manufacturing.
These films are formed using well known techniques such as CVD. Low-pressure chemical vapor deposition (LPCVD) is a special case of a CVD process, typically used for front end of line (FEOL) dielectric film deposition. In a CVD process, a given composition and flow rate of reactant gases and diluent carrier gases are introduced into a reaction chamber. The gas species move to a substrate and the reactants are adsorbed on the substrate. The atoms undergo migration and film-forming chemical reactions and a film (e.g., silicon oxide) is deposited on the substrate. The gaseous byproducts of the reaction and removed from the reaction chamber. Energy to drive the reactions can be supplied by several methods, e.g. thermal, light and radio frequency, catalysis, or plasma. A conventional CVD system typically contain gas sources, gas feed lines, mass-flow controllers, a reaction chamber, a method for heating substrates onto which the film is to be deposited, and temperature sensors. A conventional LPCVD system is similar to the CVD system except that temperature is the primary driver for the reaction of source gases.
A state of the art system for forming a medium temperature deposition oxide film (MTO) and a high temperature deposition oxide film (HTO) on a substrate utilizes a batch type LPCVD system which is depicted in FIG.
1
A. This figure illustrates a batch type LPCVD system
100
which is a hot wall furnace system including a three-zone resistance furnace
112
, a quartz reactor tube
102
, a gas inlet
104
, a pressure sensor
106
, and a wafer boat
108
. A plurality of silicon wafers
110
are vertically positioned upon the wafer boat
108
for deposition. The wafers are radiantly heated by resistive heating coils surrounding the tube
102
. Reactant gases are metered into one end of the tube
102
(gas inlet
104
) using a mass flow controller. Reaction by-products are pumped out the other end of the tube
102
(e.g., via an exhaust pump).
The state of the art system suffers a disadvantage called “depletion effects.” Depletion effects reduce gas phase concentrations as reactants are consumed by reactions on wafer surfaces. As such, wafers near the inlet
104
are exposed to higher concentrations of reactant gases. Deposition rates are thus greater for wafers placed near the inlet
104
. As a result, uniform thickness is difficult to obtain for the wafers in a batch and from batch to batch.
SUMMARY OF THE INVENTION
A process for forming a silicon oxide film, or a silicon oxynitride film, is described. The film is grown by a thermal low-pressure chemical vapor deposition process. The process can be performed in a single wafer cold wall reactor wherein a silicon source gas and an oxidation source gas are decomposed using a thermal energy source in a deposition chamber to form the film. The film is formed with a total pressure between 50 to 350 Torr and with a flow ratio between 1:50 to 1:10000, silicon source gas flow to oxidation source gas flow, respectively. The process enables forming of films having thickness less than 100 Å and greater than 1000 Å with a deposition rate between 20 Å per minute to 2000 Å per minute.
REFERENCES:
Watt, V.H.C., et al., “Direct Bonding of LPCVD Silicon Oxide Thin Film Films Deposited from N2O and SiH4,” Electrochemical Society Proceedings, vol. 95-7, pp. 573-578.
Chen Aihua
Iyer Ramaseshan Suryanarayanan
Luo Lee
Subramony Janardhanan Anand
Yokota Yoshitaka
Blakely & Sokoloff, Taylor & Zafman
Meeks Timothy
LandOfFree
Methods for silicon oxide and oxynitride deposition using... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Methods for silicon oxide and oxynitride deposition using..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods for silicon oxide and oxynitride deposition using... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3199024