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Two important points have now been established:

1. For sound device physics reasons, most RTA processes consist of high temperature, short duration anneals.

2. Damage-enhanced diffusion will only occur for a few seconds at typical RTA temperatures.

For accurate simulation of RTA, the second point is most important and often wrongly neglected. Suppose an RTA consists of a 10 second ramp up to 1000°C, followed by a 20 second anneal and a 10 second cool down. From the second point, it is apparent that most of the Total Dopant Diffusion would have taken place during the Ramp Up Phase of the RTA.

Therefore, always model the temperature ramp up accurately when simulating an RTA process. In most cases, the ramp down can be neglected, since all the diffusion has already taken place at the beginning when the silicon was still damaged.

7.7.9: Simulating Oxidation

It has already been stated that the pull down menu for simulating oxidations is the same as that for simulating inert diffusions described in the “Simulating Diffusion” Section on page 2-37. See this section for advice on selecting the appropriate pull down menu from DECKBUILD.

The default method for oxidation is Compress. In SSUPREM4 examples there are a number of examples which illustrate the use of different models for different processes and structures.

In our previous example described in the “Simulating Diffusion” Section on page 2-37, if the next temperature step is going to be at a constant temperature of 1000°C in dry O2 with 3% of HCL in the ambient, select the Dry O2 box and set HCL% equal to 3 in the Ambient section of the Diffuse menu. The following input file fragment will appear:



If the ambient is a mixture consisting of more than one oxidant, the total oxidation rate will depend on the combined effect of all species in the ambient. To specify the contents of the ambient mixture, select the Gas Flow button in the Ambient section and an additional ATHENA Gas Flow Properties Menu (Figure 7-38) will appear.

Figure 7.38. ATHENA Gas Flow Properties

If the Gas Flow components are selected, as shown in Figure 7.38, the following statement will be generated:


DIFFUSE TIME=60 TEMP=1000 F.H2O=5.3 F.HCL=0.06 F.O2=8.0 \ PRESS=1.00

One or several impurities can be present in the ambient. To set ambient in the Impurity Concentration section of the ATHENA Diffuse Menu (See Figure 7-37), check the corresponding checkboxes, and set the values using sliders and the Exp menus.

For example, by selecting the appropriate boxes and values, the following DIFFUSE statement will be inserted into the input file:



Several other parameters not included on the menu are available in the DIFFUSE statement (Chapter 6: “Statements”, Section 6.15:“DIFFUSE”). The DUMP, DUMP.PREFIX, and NO.DIFF parameters can be useful. DUMP and DUMP.PREFIX can be used to make a movie using TONYPLOT. The NO.DIFF parameter specifies that impurity redistribution will be neglected. This provides a good approximation for low temperature processes, such as silicidation.

Several other model specification statements are important for diffusion processes. These are as follows:

• IMPURITY, INTERSTITIAL, and other impurity and point defect statements, which specify model parameters (e.g., diffusivity or segregation) of these species.

• The OXIDE statement, which specifies parameters for different oxidation models.

• The MATERIAL statement, which specifies some basic parameters for all materials.

• The SILICIDE statement, which specifies silicidation coefficients.

Table 7.7 shows the basic diffusion and oxidation models.

Table 7.7. Basic Diffusion and Oxidation Models.

Process Model Assumption Recommendation
Diffuse Fermi- Default Defect in equilibrium For undamaged substrates in inert ambients
two.dim Transient defect diffusion during oxidation, and after medium dose implant (e.g., OED)
full.cpl Defect and impurity binding energy model Post high dose implant&co-diffusion effects, but execution time is high
Oxidation Vertical Planar 1D oxidation only (should never be used)
Compress- Default Non-planar with linear flow 2D oxidation (e.g. birds beak)
ViscousElastic Non-planar with non- linear flow 2D oxidation (e.g. birds beak with thick Si3N4, however, execution time is higher

For a detailed description of all diffusion and oxidation models, see Chapter 3: “SSUPREM4 Models”, Sections 3.1: “Diffusion Models” and 3.3: “Oxidation Models”.

Questions & Answers

anyone know any internet site where one can find nanotechnology papers?
Damian Reply
Introduction about quantum dots in nanotechnology
Praveena Reply
what does nano mean?
Anassong Reply
nano basically means 10^(-9). nanometer is a unit to measure length.
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
Damian Reply
absolutely yes
how to know photocatalytic properties of tio2 nanoparticles...what to do now
Akash Reply
it is a goid question and i want to know the answer as well
characteristics of micro business
for teaching engĺish at school how nano technology help us
Do somebody tell me a best nano engineering book for beginners?
s. Reply
there is no specific books for beginners but there is book called principle of nanotechnology
what is fullerene does it is used to make bukky balls
Devang Reply
are you nano engineer ?
fullerene is a bucky ball aka Carbon 60 molecule. It was name by the architect Fuller. He design the geodesic dome. it resembles a soccer ball.
what is the actual application of fullerenes nowadays?
That is a great question Damian. best way to answer that question is to Google it. there are hundreds of applications for buck minister fullerenes, from medical to aerospace. you can also find plenty of research papers that will give you great detail on the potential applications of fullerenes.
what is the Synthesis, properties,and applications of carbon nano chemistry
Abhijith Reply
Mostly, they use nano carbon for electronics and for materials to be strengthened.
is Bucky paper clear?
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
so some one know about replacing silicon atom with phosphorous in semiconductors device?
s. Reply
Yeah, it is a pain to say the least. You basically have to heat the substarte up to around 1000 degrees celcius then pass phosphene gas over top of it, which is explosive and toxic by the way, under very low pressure.
Do you know which machine is used to that process?
how to fabricate graphene ink ?
for screen printed electrodes ?
What is lattice structure?
s. Reply
of graphene you mean?
or in general
in general
Graphene has a hexagonal structure
On having this app for quite a bit time, Haven't realised there's a chat room in it.
what is biological synthesis of nanoparticles
Sanket Reply
what's the easiest and fastest way to the synthesize AgNP?
Damian Reply
types of nano material
abeetha Reply
I start with an easy one. carbon nanotubes woven into a long filament like a string
many many of nanotubes
what is the k.e before it land
what is the function of carbon nanotubes?
I'm interested in nanotube
what is nanomaterials​ and their applications of sensors.
Ramkumar Reply
how did you get the value of 2000N.What calculations are needed to arrive at it
Smarajit Reply
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Source:  OpenStax, Solid state physics and devices-the harbinger of third wave of civilization. OpenStax CNX. Sep 15, 2014 Download for free at http://legacy.cnx.org/content/col11170/1.89
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