Download EE 330 LAB Report #5

2012
Iowa State University
Che, Xiaoyu
[EE 330
LAB REPORT #5]
Lab 5: Creating Bonding Pads
August 31, 2012
[EE 330
LAB REPORT #5]
Introduction
In this lab we will create a resistor in the layout view and also investigate the design of a basic
bonding pad and simple ESD protection circuitry. The protection circuitry as well as the human body
model will be drawn in schematics and then realized in layout view.
Steps
1. Layout of a resistor
a.
b.
c.
d.
Calculate the width of the resistor to minimize it.
Draw the resistor with poly.
Attach via, metal and res_id layer.
Check whether the resistance is accurate. If not, make some adjustment.
2. Layout of a bonding pad
Create a bonding pad comprised of stacked layers of metal1, metal2, metal3 with a pad opening with the glass
layer. Use the appropriate stacked vias to interconnect these metal layers. Use the maximum possible number
of vias to connect two adjacent metal layers. The pad should meet design rules and the opening in the glass
layer is to be 78µm x 78µm, but as small as possible.
3. Pad Protection Circuitry
a. Create a schematic of the ESD protection circuit.
b. Create a layout of the ESD protection circuit.
c. Diodes: p+ and n+ diffusions inside an n-well.
4. Human Body Model
Create a human body model according to the figure. Set the starting voltage of the charged capacitor in different
numbers and simulate the circuit to see the output voltage.
Iowa State University |Xiaoyu Che
1
August 31, 2012
[EE 330
LAB REPORT #5]
Lab Result:
Figure 1&2: Resistor
Analysis: This is the resistor created with poly. After calculation I get that it should be 10 rows
if the length and width are the same. But when it was created I found the resistance to be a
litter bigger so I made some adjustment.
Iowa State University |Xiaoyu Che
2
August 31, 2012
[EE 330
LAB REPORT #5]
Figure 3&4: Bonding pads
Analysis: The figure shows the bonding pads with 3 layers of metal and the glass. The vias can
be seen everywhere on the pad which are very compact. The size of glass is 78µm x 78µm
while the size of pad is 96µm x 96µm. They do satisfy the rules.
Iowa State University |Xiaoyu Che
3
August 31, 2012
[EE 330
LAB REPORT #5]
Figure 5: Schematic of the protection circuitry
Iowa State University |Xiaoyu Che
4
August 31, 2012
[EE 330
LAB REPORT #5]
Figure 6&7: layout of the protection circuitry
Analysis: This is the layout of the protection circuitry. In the diodes, the p+ and n+ rectangles
are attached to each other and both in the n well and dio_id layer. The diodes can be
recognized in extraction and LVS. The figure shows that the LVS is successful.
Iowa State University |Xiaoyu Che
5
August 31, 2012
[EE 330
LAB REPORT #5]
Figure 8: Schematic of the human body model
Figure 9-17: Output voltage with different input voltages
Time scale: 5us
Iowa State University |Xiaoyu Che
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August 31, 2012
[EE 330
LAB REPORT #5]
250v:
500v:
1000v:
2000v:
Iowa State University |Xiaoyu Che
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August 31, 2012
4000v:
[EE 330
LAB REPORT #5]
8000v:
10000v:
From the figures we know that for
every input the output voltage is
always bigger than 5v. So the circuit
is unsafe. If we change the
standards, for example, the voltage
below 8v won’t destroy the circuit,
we can say that the device belongs
to class 1c.
Iowa State University |Xiaoyu Che
8
August 31, 2012
[EE 330
LAB REPORT #5]
Conclusion
This time we learnt the procedure of creating a resistor in layout. Calculation is needed before
drawing and adjustment is also necessary after drawing. We also created a bonding pad and a ESD
protection circuitry and then ran the simulation to see the voltage of the output and whether this
voltage is OK.
Iowa State University |Xiaoyu Che
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