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hello everyone welcome to my YouTube
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channel called silicon vsi today we will
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discuss about how to solve antenna
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effect in vsi so before moving to that I
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just want to explain what is the antenna
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effect in vsi so let's start the antenna
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effect also known as the plasma induced
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damage occur during the manufactur
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process of vsi it's happen when long
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metal interconnect act like antenna
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collecting charge during the plasma
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itching which can is the Gate oide of
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the transistor so here I just want to
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give you brief explanation about what is
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the antenna or what is the antenna ratio
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you should draw antenna
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area so this ratio should not be greater
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than some some number this number it
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depend on the technology it will be vary
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with according to technology so we just
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want to understand this thing how this
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ratio is effect to transistor so first
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thing to avoid the antenna effect my our
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first movement will be you know we need
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to place device as close as possible our
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main aim is to reduce the metal area so
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let's assume this gate and this gate has
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put this two device as close as possible
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so that we can reduce the metal area so
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this is the first step to avoid the
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effect you should place as close as
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devices which is connected to each other
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so this is the first step second step is
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use metal jumper so if device is not
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possible to place near to each other
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second step is use metal
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jumper so let's assume we are getting
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antenna error in Metal 2 so we should
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always go for a higher metal so let's
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2 so we should jump for metal 3 not
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metal 1 if you know already why metal
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not it is okay if you don't know just do
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comment I will give you reply in the
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comment so so do you think friend this
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metal three like the cut which I did
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here in this region it is
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okay no this is not okay we should cut
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the metal to near to the let's
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assume from here like I I cannot say
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this is the gate it it could be a drain
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two gate is not like here should not
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connect like this is the drain and the
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drain signal is going to gate so so
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better practice is we should always cut
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M2 or wherever we are getting the
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antenna we should cut near to the gate
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only we should reduce this area as much
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as possible we should not cut here we
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here like this way so this is M3 M2 M2
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so this is the best practice so
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interviewer may be ask you which how you
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will choose cut like from where you will
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jump which location that is very
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important here you should
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always tell them like I should cut it
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from here not from in this location but
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Jumper near to the gate in conclusion we
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should always take care we should cut
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the metal wherever we are getting
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antenna we should cut near to the gate
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area gate region only so this is right
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this is wrong so second thing is this
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metal jumper we should use metal jumper
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if metal jumper is not possible the
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design is fully congested we cannot
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place the device near to each other
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third step will be an and iode this is
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the very important thing to Sol the
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antenna error let's assume this is the
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drain so if we are not going like we
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cannot jump towards the top side and we
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cannot place near to each other we
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should put antenna diode in this
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location and that diode should always a
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reverse bias that is very important
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thing we should put that diode near to
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the device only where where gate is
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present we should not put here the diode
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this is wrong location we should always
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put antenna diode near to the gate where
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we are getting the antenna if
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error now second one another thing very
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important thing is how this diode will
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work do you know friends how this diode
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will work so during this diode will
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only during the fabrication
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process very high so this diode will
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work as a resistor so whatever current
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will be there it will choose this path
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and it will discharge in normal
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condition like in circuit condition this
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diode will always work as a reverse B
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because of a lower temperature so this
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is a very important thing here one
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question will rise how this diode will
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work so you have to tell like during the
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fabrication process this diode because
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of the high temperature this diode will
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work as a resistor so this is very
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thing now so we have now the
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last method is use the dummy fill you
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can also use dummy fill to balance the
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charge distribution and minimize the
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charge accumulation on the specific
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now I will tell you one question so you
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should give me the answer
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so if you don't know just if you know
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you just do comment or don't know you
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also do comment I will let you know the
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answer this is very important question
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so interviewer asks you I'm getting
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error in this antenna error in y
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crosssection so this is y 7
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so obviously if this is y 7 then this
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will be metal 7 and on the top of metal
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8 will be also there this is Metal
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8 so interor are saying like I'm getting
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7 how like they will ask you
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why not in M7 and M8 why I'm getting
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only antenna error in Ys
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7 because if you think like if you see
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Formula metal area upon gate area or Y
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area so but if you see here the Y area
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is very less as compared to metal 7 or
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8 because always Y is under either metal
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7 or metal 8 then why I am getting
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interna area in y 7 only why not M8 or
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M7 so if you know the answer please let
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know this is very interesting question
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so nowadays people are asking this
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company so that's all my friend if you
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have any question just let us know thank
