Olid State Electronic Devices – Report.pdf

Department of Electronics Page | 1 Semiconductor Devices Laboratory Advanced Program... TCAD Examples Department of Electronics Page | 2 Semiconductor Devices Laboratory Advanced Progr

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Department of Electronics Page | 1

Semiconductor Devices Laboratory (Advanced Program)

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> The purpose of this lab is to learn how to use Atlas — Silvaco TCAD Tool

> We learn how to use the Atlas command language to define a semiconductor device

> We examine BJT Characteristic

PREPARATION FOR LAB 2

> Install Silvaco Tool

> Read User manual

REFERENCE

1 Atlas User’s Manual

2 TCAD Examples

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characteristic: Ic = f(Vcr) at Ip =2.10-5A

Instruction:

~ In this experiment, there are some missing regions Define them by using an oxide region

- To calculate the input characteristic In = f(Vpe) at Vcz =5V, a 5V voltage source is applied at the collector Then, solve the voltage at the base from 0V to end point (for example 1V) The

code

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Laboratory 2:

BJT

for this step is shown below:

- Ta calculate the output characteristic Ic = f(Vce) at Ip = 2.10-5A, a current source is applied at the basg Then, solve the voltage at the base from 0V to end point (for example 12V) The code for thig.step 1g shown below: VCO

Say qutỆrJtja†a L.siy,paster

aalira wanllantarHf A wrotanHf 2Ã x7 final=19 1 namasnrallantar

The statement “contact name=base current” is used to switch a current source at the base

Note: in the simulation, the emitter is always connected to the ground (OV)

Check:

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Laboratory 2:

BJT

output

Data trêu TPSbjt2.log

> In TonyPlot Window display structure, right click and choose “Display ” Then choose

to display: Contours and Electrodes Capture the result

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> On Toolbar menu, choose Tools © Cutline Draw a horizontal cutline at 2 micron Show

the concentration allocation with respect to x-coordinate Capture and explain why we have this graph

The graph shows how the concentration of dopant atoms varies across different parts of the Bipolar Junction Transistor (BJT) along the two-micron lines This variation pattern closely resembles the data representing the desired doping profile

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> Right click, choose to Display Electric Field Capture and explain the graph

The graph confirms theoretical expectations for BJTs We observe a small rise in the

electric field around the 6-micron mark, which coincides with the location of the base

region A significant increase in the electric field then occurs between 9 and 12 microns, corresponding to the emitter region

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BJT

> Then, choose to Potential Capture and explain the graph

Section 1 from Ib2bjt2.str

(-0.200 , 1.999) to (15.200 , 1.999)

The potential graph is equivalate to the electric field graph

> Then, choose to Total Current Density Capture and explain the graph

Potential (V)

The graph shows the total current density changing across the device On the left side, the current density gradually increases In contrast, the right side shows a steady decrease in current density, followed by a sharper drop until it reaches a specific point in the middle This indicates that the current density is building up at different rates on either side of the device and converging towards a central point

Department of Electronics

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- The input characteristic Is = f(Vpe) at Vcz = 1V, 3V, 5V, 7V, 9V, 12V

- The output characteristic: Ic = f(Vcg) at Ip = 1.10-5A, 2.10-5A, 4.10-5A, 8.10-5A, 10-4A

Show all the input characteristics in one graph and all the output characteristics in the other graph Instruction:

- In this experiment, we need to simulate and show the input characteristic at 6 conditions of Vce We show the example for two conditions:

solve veollector=1

save outf=bjtdatal str

master solve veollector=3

save outf=bjtdata2.str master

load inf=bjtdata1.str

master log

outf=bjtdatal log

solve vbase=0.0 vstep=0.05 vfinal=1

name=base load inf=bjtdata2.str master

log outf=bjtdata2.log

solve vbase=0.0 vstep=0.05 vfinal=1 name=base

Use “tonyplot -overlay” to show all the characteristics on a graph

Check:

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> From the input characteristic, calculate the Veron) at each condition Fill the table 1

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From the table, comment on the trend of the input characteristic

As V_CE increase VBE(ON) would also increase

> From the output characteristic, calculate the Vcgsa at each condition Fill the table 2

pata Fon one les

From the table, comment on the trend of the output characteristic

As I_B increase VCEsat would also increase

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characteristic: Ic = f(Vec) at Ip = 2.10-5A

Instruction:

~ Remember that the emitter is always connected to the ground (OV) In this case, we need to set the voltage at the base and the collector negative

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BJT

Data from LS pit2.log

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BJT

> From the output characteristic, calculate the Vecsat at Ip = 2.10-5A

The graph displays the amount of concentration doping on different regions of the BJT where the 2 micron lines pass through It can be compared with the data provided by the requirement

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matches the desired characteristics

> Right click, choose to Display Electric Field Capture and explain the graph

Department of Electronics

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Then, choose to Total Current Density Capture and explain the graph

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BJT

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- Nog= 8,15.1018 em-3 , Npoc = 2,67.1014 cm-3, Nap=5,12.1016 cm-3

- Le=4 um, Lg =9 um, Lc = 12 wm

- We =4 wm, We = 6 um, Wc = 8 wm

~a=2 um

The length of metal contact is 1 um

The spacing of x-axis and y-axis are 0.2um and 0.1m

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~ Devide the structure into many regions

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ATLA Data from AApit1 log

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~ Data lên KH sĩ

~ G

Microns

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> Then, choose to Total Current Density Capture and explain the graph

Section 1 from ex4bjt1 str (0.000 1.995) to (12.000 1.995)

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Note: If you want to display potential, electric field,

after the electrical simulation step

Tiêu đề	BJT
Tác giả	Nguyễn Văn Cường
Người hướng dẫn	Nguyộn Trung Hiộu, PTS.
Trường học	Ho Chi Minh City University of Technology
Chuyên ngành	Solid State Electronic Devices
Thể loại	Laboratory Report
Thành phố	TP.HCM

Định dạng
Số trang	27
Dung lượng	3,76 MB