# 8.21 Sspd_chapter 6_part 7_introduction to athena 2_process simulator

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SSPD_Chapter 6_Part 7 is continuation of "Creating Device Structures".Here we give 'geometrical etch','reducing grid points','reflecting the half structure to get the full structure','specifying the electrodes' and 'saving a structure file'.

SSPD_Chapter 6_Part 7_Introduction to ATHENA2

SECTION 7.7 Background of ATHENAcontinued.

7.7.2. Creating Device Structure using ATHENA

7.7.2.5. Simple Geometrical Etches

The next step in this tutorial process simulation is to define the polysilicon gate definition. (Implant and thermal steps will be discussed in later Section :“Choosing Models In SSUPREM4”). To set a geometrical etch step, select Process→Etch→Etch... from the Command menu of DECKBUILD. The ATHENA Etch Menu (Figure 7.24) will appear.

The Geometrical etch is the default method. Other methods will be discussed in later Section called “Deposition and Wet/Dry Etching using the Physical Models in ATHENA/ELITE”. Select Polysilicon from the Material menu. This example will use a polysilicon gate edge at x=0.3 and set the center of the gate at x=0.0 for the initial grid. Therefore, polysilicon should be etched to the right from x=0.3. To do so, select Right from the Geometrical type , and set the Etch location to 0.3. This will give the following statement: # POLY DEFINITION

ETCH POLY RIGHT P1.X=0.3

The structure created by this ETCH statement is shown in the left hand plot of Figure 7.25.

You can obtain an arbitrary shape of geometrical etching by using the Any Shape button. For example, to make a tilted etch, specify X and Y locations of four Arbitrary points as shown in Figure 7.26 .

The following four etch lines will be inserted into the input file:

# POLY DEFINITION

ETCH POLY START X=0.2 Y= -1

ETCH CONT X=0.4 Y= 1

ETCH CONT X=1 Y= 1

ETCH DONE X=1 Y= -1

If this input file fragment is run instead of the previous one (using the INIT statement from the History capability), the structure after this etch sequence will appear as displayed in the right hand plot in Figure 7.25. ATHENA etches all polysilicon material within the specified polygon [ polygon is defined by the points P1(x= 0.2,y= -1),P2(0.4,+1),P3(1,1)&P4(1,-1)]. The polygon etch can consist of any number of points. If you use the Insert button, an additional point will appear after the currently selected point.

Figur7.25: Structure Created by Etch Statement (a)Right etch (b) Any Shape.

Figure 7.26. ATHENA Etch Menu for arbitrary etch.

An additional option for geometrical etching is a dry etch with a specified thickness. This can be used for spacer formation as follows: deposit an oxide of a specified thickness (e.g., 0.5µm) right to poly-Si and then etch the same thickness again beyond x = 0.6µm.

# CLEAN GATE OXIDE

ETCH OXIDE DRY THICK=0.02

# SPACER DEPOSITION

DEPOSIT OXIDE THICK=0.5 DIVISIONS=8

# SPACER ETCHING

ETCH OXIDE DRY THICK=0.53

The dry etching step etches the specified material in the region between the top (exposed) boundary of the structure and a line obtained by translating the boundary line down in the Y direction. The etch distance is specified by the THICK parameter. Figure 7-27 shows the resulting spacer.Figure 7.27 is given in the next module.

#### Questions & Answers

What fields keep nano created devices from performing or assimulating ? Magnetic fields ? Are do they assimilate ?
why we need to study biomolecules, molecular biology in nanotechnology?
?
Kyle
yes I'm doing my masters in nanotechnology, we are being studying all these domains as well..
why?
what school?
Kyle
biomolecules are e building blocks of every organics and inorganic materials.
Joe
anyone know any internet site where one can find nanotechnology papers?
research.net
kanaga
sciencedirect big data base
Ernesto
Introduction about quantum dots in nanotechnology
what does nano mean?
nano basically means 10^(-9). nanometer is a unit to measure length.
Bharti
do you think it's worthwhile in the long term to study the effects and possibilities of nanotechnology on viral treatment?
absolutely yes
Daniel
how to know photocatalytic properties of tio2 nanoparticles...what to do now
it is a goid question and i want to know the answer as well
Maciej
characteristics of micro business
Abigail
for teaching engĺish at school how nano technology help us
Anassong
Do somebody tell me a best nano engineering book for beginners?
there is no specific books for beginners but there is book called principle of nanotechnology
NANO
what is fullerene does it is used to make bukky balls
are you nano engineer ?
s.
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.
Tarell
what is the actual application of fullerenes nowadays?
Damian
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.
Tarell
what is the Synthesis, properties,and applications of carbon nano chemistry
Mostly, they use nano carbon for electronics and for materials to be strengthened.
Virgil
is Bucky paper clear?
CYNTHIA
carbon nanotubes has various application in fuel cells membrane, current research on cancer drug,and in electronics MEMS and NEMS etc
NANO
so some one know about replacing silicon atom with phosphorous in semiconductors device?
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.
Harper
Do you know which machine is used to that process?
s.
how to fabricate graphene ink ?
for screen printed electrodes ?
SUYASH
What is lattice structure?
of graphene you mean?
Ebrahim
or in general
Ebrahim
in general
s.
Graphene has a hexagonal structure
tahir
On having this app for quite a bit time, Haven't realised there's a chat room in it.
Cied
what is biological synthesis of nanoparticles
what's the easiest and fastest way to the synthesize AgNP?
China
Cied
how did you get the value of 2000N.What calculations are needed to arrive at it
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