ME/EE 685 Homework #3 Due 3/10/08
By Tricia Nguye
1
Objective
1.1
To design an RF MEMS switch in CoventorWare using the PolyMUMPS
process and the dimensions of Design B and Design C. To add wire traces and a bump pad to Design
B & C. To deliver masks containing the necessary cells and
a top cell for Design B & C show cell hieracrchy as well
as the 3D structure of 1cm x 1cm.
2
Design Requirements
Figure 1
Design B & C Dimensions
2.1
Wire traces are 7 um thickness and bump pads of 50 um x 50 um
at the Poly0 layer.
2.2
Provide enough length of the traces and pads to enable a spacious
and convenient access for probing.
2.3
The sub-dies should be preferably 1 mm x 1mm.
2.4
Array these sub-dies to a complete die of 1 cm x 1cm.
3
Methods (in CoventorWareฎ)
3.1
Create a cell called Basic_Anchor to be used for both
Design B and Design C. It is a 4um x 4um square applied to Anchor1,
Poly1Poly2Via, and Poly0 layers.
3.2
Create a cell called Basic_Hole to be used for both designs.
The mask provides the 10um diameter Etch Holes applied to Hole2,
Poly2, Metal, and HoleM layers.
3.3
Create a cell called Meanders that contain the meanders
at the ends of the switch. The meanders are 4um thickness with
4um spacing. Apply this to only the Poly2 layer.
3.4
Create a 1cmx1cm cell that contains the 1cm x 1cm square
sub-die footprint applied to only the GND layer.
3.5
Create a cell called Traces that contain the dimensions
required for the trace and bump pad. Add this to Poly0 layer
only.
3.6
For Design B, create DesignB_RFSwitch that contains the
dimensions of the switch. This layout will apply to the Poly2
layer and has the dimensions as shown in Figure 1. This footprint
will not contain the meanders at the ends. They will be added
on later with the Array Reference function.
3.7
Using the Array Reference function, add the Basic_Anchor,
Basic_Hole, and Meanders cells to the appropriate
locations in the DesignB_RFSwitch cell.
3.8
Using the Reference function, add the Traces cell to
the DesignB_RFSwitch cell. Now add the 1cmx1cm
cell to complete the sub-die that contains the Design B switch.
3.9
Create another cell called DesignB_Die that contains
the 1mm x 1mm square boundary for the whole die and apply to
GND layer only. Use the Array Reference function to add the
DesignB_RFSwitch sub-dies into the die and be sure to create
10 rows and 10 columns of the sub-dies. This completes the requirements
for Design B.
3.10
To create Design C, create a new cell called DesignC_RFSwitch
that will contain the footprint for the switch design per Figure
1. This first piece of the switch will include the side meanders
but not the Meanders cell that will be added to the ends
at a later time.
3.11
Use the Array Reference function to add Basic_Anchor,
Basic_Hole, and Meanders cells to the appropriate
locations on the DesignC_RFSwitch cell.
3.12
Use the Reference function to add the Traces cell followed
by the 1cmx1cm cell to complete the sub-die for the Design
C switch.
3.13
Create another cell called DesignC_Die that contains
the 1mm x 1mm square boundary for the whole die and apply it
to GND layer only. Add the DesignB-RFSwitch sub-die cells
via Array Reference to create 10 rows and 10 columns of sub-dies.
This completes the requirements for Design C.
4
Deliverables
4.1
The following results are the various cells that were useful
for both Design B and Design C.
Figure
2 Meander cell
This cell is used with Array Reference to add the meanders at
the ends of the switch.
Location of 1 Meander cell in Design B
|
|
Location of 1 Meander cell in Design C
|
|
Figure
3 Location of cells
Figure
4 Basic_Anchor cell
The 4 um x 4 um square that makes up the anchor masks are applied
to Poly0, Poly1Poly2Via, and Anchor1 layers.
Figure
5 Basic_Hole cell
This 10 um diameter circle makes up the etch holes and are applied
to the Hole2, Poly2, Metal, and HoleM layers.
Figure
6 Traces cell
This trace and bump pad layout was created in Poly0 to be added
to each design and can be manipulated or changed at anytime.
4.2
The following deliverables are for Design B requirements.
Figure
7 DesignB_FSwitch contains
the meanders, the anchors, and the etch holes.
Figure
8 Design C with the traces
and bump pad
Figure
9 Die
Contains 10 rows and 10 columns of the DesignB placed in a 1cmx1cm
sub-die using the Array Reference function
Figure
10 3d image of Design
B
Figure
11 Another 3d view of
Design B
4.3
The following are the results for Design C.
Figure
12 Design C cell
Contains the side meanders and applied to the Poly2 layer only
The end meanders were added via Array Reference
Figure
13 Design C full mask
with Anchor, Etch Holes, Traces/Bump Pad added
Figure
14 Design C in a 1cmx1cm
sub-die
Figure
15 Design C sub-dies arranged
in rows and columns of 10 to make 1 die
Figure
16 Three different views
of Design C in the 3d model
5
Summary
|
Cell
Name
|
Description
of cell
|
Layers
it was applied to
|
|
Basic_Anchor
|
4um
x 4um square anchor centered around the origin
|
Anchor1,
Poly1Poly2Via, Poly0
|
|
Basic_Hole
|
10
um diameter circle centered around the origin
|
Hole2,
Poly2, Metal, HoleM
|
|
Meanders
|
End
meanders with dimensions given in Figure1
|
Poly2
|
|
Traces
|
Contains
the traces (7um thick) and the bump pad (50um x 50um)
|
Poly0
|
|
1cmx1cm
|
Contains
the 1cm square that acts as the boundary to the sub-die
|
GND
|
|
DesignB_RFSwitch
|
Design
B switch
|
Poly2
|
|
DesignC_RFSwitch
|
Design
C switch
|
Poly2
|
|
DesignB_Die
|
Design
B sub-dies placed in the die using Array Reference
|
GND
|
|
DesignC_Die
|
Design
C sub-dies placed in the die using Array Reference
|
GND
|
6
Conclusion
The
key to completing this assignment efficiently is through organization
of cells and manipulation of Array Reference. If there are repeatable
features in the design, it is best to create a separate cell.
If modifications are required down the road, it would be much
easier to modify it once in the cell rather then repeat it for
every place that feature is needed. Also, creating separate
cells is effective for creating several design variations. In
this assignment, it was much quicker to create the anchor, hole,
trace, and meander cells once and apply it both Design B and
Design C.