How to draw a BJT layout?

[kbd]

I normally do layout for MOS and never had drawn a BJT... How do you draw it? what must I check while drawing it?; regardless of DRC and LVS...
Thanks...

 

[learn17]

BJT Layout

for bjt the emitter base and collector are the terminals that should be considered. take note that in bjt collector may always be connected to VSS or grouund

 

[andy2000a]

BJT Layout

cmos only draw "rectangle" but some BJT design
use circual or multi emitter area , and also cause
LVS /DRC fail ..

and BJT design usually use 1 metal only
some connection use "diffusion"
and device iso by "epi " some device use NBL

 

[Shohdy]

Re: BJT Layout

Hi,

The BJT layout mainly depends on the technology you are using...its shape differs from one fab to the other and from one technology to the other. Also the BJT usually has two or three fixed shapes with diffrent sizes for each technology, and it is provided in the design kit you are using.

So you don't need to draw it yourself.

Regards,
Shohdy

 

[aisis]

Re: BJT Layout

In doing the layout of BJT we usually place them frame to frame to save area for the chip. we also avoid passing wires on the three terminals especilly on emitter area.
We have a matching considerations also for bjt (common centroid). Ex. Q1 & Q2<0:7> needs to place common centroid. You can place them 3rows and 3columns w/c is equal to 9. The center 1 is Q1 & 8 pcs of Q2 is surrounding Q1. This is the manner of doing common centroid BJT.

 

[learn17]

Re: BJT Layout

what is the function of the diode you are talking about is it a diode or it functions as a memory cell?

 

[kbd]

Re: BJT Layout

does it means that one part of the BJT is connected to substrate, which is actually connected to vss?

Added after 2 minutes:

Can someone give a a simple sketch of BJT's layout... if possible connected to another BJT.

 

[aisis]

Re: BJT Layout

Hi leam17,

I am not reffering to a diode my example is purely BJT transisitors Q1 & Q2 are bjt transisitors place in common centroid. thanks

 

[Shinji]

BJT Layout

can anyone post 2d pics of a bjt transistor?

 

[learn17]

Re: BJT Layout

Sorry for confusing but I really mean is bjt, does this bjt used as diode or is this was used as array memory cell (like a flash memory cell)

 

[mac_user]

Re: BJT Layout

Hi aisis,

Are you refering to a ovonics technology?

Thanks

 

[aisis]

Re: BJT Layout

my above example is not only for memory or ovonics technology, this common centroid can be use for any process or technology as long as we need to consider the matching of the 2 transistors. this is just an example of common centroid for bjt transistor to maintain the environment of the 2 transistors.