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Is there anyone who's used UMC 28nm for analog circuit before? In this process, the POLY high density checking window is 1mmX1mm stepping 500um, is that possible? It's a big question mark.
An auto-generated layout probably has no taps, hence tap-density type errors. It's telling you "OK, your turn to step in and finish the job" most likely.
There may be application specific reasons to set different defaults for individual spacing constraints, asking for a general answer doesn't make much sense however. If track to track spacing is marginal, you may want to mitigate those constraints that are not essential for design density. A trivial explanation could be that the DFM rules had been e
Use foundry provided density rules - as freebird stated above.. these are kind of DRC rules.. Calibre, PVS, Assura can do a density check. Back to Basics: Metal density - is a point function, and therefore various functional representations are possible, {there is nothing like absolute value of (...)
The density rules allow are aimed for DFM (Design for Manufacturability), so overall you should try to make them happen. See this article. You don't need to fill them with "active" metal, you can usually 1) fill with metal and ground it --- make sure to not add extra capacitance to
I see no reason not to, but depending on how the density rules are constructed you may or may not get a benefit (global density, vs an anywhere-window that requires density to be met within any field of view). That, and since contacts mean metal you would be walling a potential routing lane(s) - maybe you want to map out (...)
You should have a different electrmogration rule for AC (zero average), which Irms would index rather than Idc. Irms of course works fine for DC signals against a DC rule, too. You just have to make sure your basis matches your application. Irms may also pertain to resistor power-density rules, similarly.
1. consider the maximum current density of your metal in the specs. 2. place 10 x 10u metal traces in parallel 3. you can also insert slots on yourself. But if they are nice, they'll ask if it's ok that they will do. Also they just check design rules and give it back to you in case of violations. And yes, it's because of metal density.
Where do find the pdf for current density rule in PDK. Usually in the Design rules or Electrical rules.
Automatic insertion of metal to meet the metal density rules as specified by a foundry for a given placed and routed IC in 28nm process is my project as of now. And I need to know certain stuff as I have no idea.. 1) Why do we prefer ASIC and full-custom designs rather than FPGA ? 2) I need bit of Understanding o
STI, shallow trench isolation, is more repeatable and finer than old-school LOCOS. Packing density is the goal. But it can come at a cost because the trench and refill can add higher stresses / strains that make devices sensitive to local geometry. density rules are for lithographic field loading, and at some extremes of sparseness the (...)
Questions : 1. Why do we have STI ? specially in lower technology nodes compared to larger nodes ? 2. Why do we need to meet minimum density rules ? What's the issue if density is low at some areas causing a groove during cmp ? Why is the planarity needed ? 3. What is requirement to put dummy's at top and bottom more stringent at lower (...)
This all depends on the signal attributes of interest. Typically upper levels are thicker and may have looser layout rules (esp. in RF and power oriented processes) so routing on M9 will cost you density. Routing on M1 will cost you more series resistance, capacitance to substrate, and impose a lower max current density (metallurgy being (...)
Pattern density is a way of setting a minimum uniformity of etch-loading, especially older wet etches suffered from depletion of the active etchant in areas where more material is being taken off, less where the load is light, leading to local variations in W, L of whatever layer is in question. I'm not sure whether these rules have "gone away"
usualy poly density is about 15% per die area and metal about 30% - and higher. For min max you really have to pull out the process rules.
At some point film stress / strain can become a reliability issue (forming hillocks, hurting planarity and maybe even photolithography). There is also a local layer density upper and lower bound, which a semi-infinite slab would violate. Above a certain width you ought to see slotting rules that force these issues back into their "box". The rul
HDB3 ( High density Bipolar 3) is used primarily in Europe for 2.048MHz (E1) carriers. This code is similar to BNZS in that it substitutes bipolar code for 4 consecutive zeros according to the following rules: If the polarity of the immediate preceding pulse is (-) and there have been an odd (even) number of logic 1 pulses since the last substit
Typical VIA current density is 1mA/VIA
Metal current density is usually evaluated by mA/um. For many processes, it is around 1mA/um for continuous current.
Current density is always I/A. The question is, what is your true linewidth and your true film thickness at the worst case feature (and where is it)? And you get repeat that for every metal layer. Most foundries give you simple mA/um or mA/contact rules to follow, which would embody the deltaL, deltaT effects.
Yez, but I mean is this a good way to connect 2 planes? Does this follow the design rules? I would only use a high density grid of vias like that if there was a very large amount of current passing through that connection.
Hi All, I am able to run assura drc without any errors but it is not listing all the errors. It is just listing density errors. but when i checked in rules file all the rules are there in rule file. can anyone say what might be the problem? Regards, Sree
There are different types of DRC violations. * Spacing violation * Minimum width Violation * Latch-Up Violation * Metal density Violation * Minimum Area violation The list goes on. These days many more new rules are being added as the technology shrinks.
In our stdcell library, most often we satisfy diffusion density rules by first filling with decap cells. Otherwise, I have also seen filler cells that contain tied off "spare" transistors. Both these types of cells add to the leakage current, which is something we want to control. Has anyone had experience using a filler cell that includes float
I passed pre-gds DRC check. Now running the DRC check with my layer-gen gds file, I am getting all sorts of coverage errors. 'M1 area coverage marker... poly area coverage marker...' I passed density rules during my pre-gds run. So now i don't know what to makes of these now. No numbers of any kind are given (min, max, or whatever). So I am wo
i mdae layout of inverter in UMC 90 nm technology.. whern i run DRC it's showing many errors like .. metal 1 coverage must be larger than 20% over lacal 100um*100um area step 50um It is M1 density error. Your need to fill more M1. (which i doubt in inverter) probably your instance layer is not at proper place and size.
How mach it important? What will happen if I violate the density rules leading to dishing of shallow trench isolation?
May be this has nothing to do with the PIP cap, but with the metal density rules? If this is an isolated layout with only these 3 metal lines, density rules have to be met, which require metal widths > min. width for "isolated" wires. As the top metal very often is thicker than the lower level metals, also its "isolated" (...)
As per my knowledge, Going to down technologies following are the some of the issues we critically find out.... 1. WPE 2. LOD 3. density. 4. Lot of DFM and Yield related rules. 5. More conservative OPC rules. These are upto 65nm. But coming to particularly 45nm, In some of the foundries I heard there are problems with Dummy poly (...)
Friends, Please share DFM rules for 65nm/45nm technologies. What kind of rules added in DRC apart from guideline like spacing, overlap, density, no of contact etc. Also let me know what is Wbp and Lbp. Thanks in advance Regards Vilas
To fill-up the metal density, you should use "tailing" utility of your technology .. It will fill-up the spaces automatically ( of course by spacing and dimensions rules are considered ) Tailing is a special pattern that consists of metal,PO,PP and sometimes N-WELL layers.. ( or DTI pattern)
There are current denisty rules for the contacts of the transistors also, so your device needs to be wide enough to satisfy the current passing through it as well. If you size your devices accordingly, then I don't think the metal width should be an issue. Also you want to make the width of your metal tracks a good bit wider than the maximum curre
Besides the etching process effect, some optical effect during fabrication has more impact, specially for deep sub-micron technology. More uniform metal density helps the lithography.
Bipolar vs. CMOS (performance) Compared to CMOS, bipolar transistors o have lower parametric variance o can operate with higher supply voltages o have higher device gain (higher rout) o can operate with higher output current density, and thus lower o parasitic capacitance for a given current o maintain current gain over decades of collector
any body know about dfm and what are the matal density rules if any body have manuals please fwd to me
Hi , Can someone associated with a FAB explain the basis behind fixing the DRC rules - especially ones like notch , dogbone ,metal density , interlayer spacing etc. How are these failure modes identified ? For metal density, you draw additional metal layer in places where it is possible. Basically in a design,
Protel has many rules, and often confilcts each other. I meet a question about trace width rule. for example: the trace witdth of net class D is 1.3mm; the whole board is 1.8mm. But actually D is still 1.8mm. I don't know why the added design rule is of no effect. Besides I feel the FBGA components are very trouble Who can give m
You can use Voltage Strom from cadence to rectify EM problems.... You can fix this by increasing the width of the metal but if it is excceding too much then u need to metal slotting which is dividing the lines on the metal to reduce the weight so tht it will not destroy ur silicon dioxide.. Electromigration is the one which depends upon the cur
electromigration can be avoided by taking care that the current density in the metal strip is low....
I doubt without knowing anything about your board someone can recommend a strategy for you but whe autorouter fails it ususally has one of the following reasons 1- Some rules prevent autorouter to succeed you have to review all the rules 2- density of your board is too much, you have to make room for autorouter
which tool can reading GDS file and check poly or metal density ??? some Fab reguest should add dummy metal or dummy poly
Sorry mdcui, there are two different issues: 1. Metal density should be controlled. That is because of dry etch and chemical polishing. 2. Slot rules in wide metal tracks. That is because to avoid delamination because of mechanical stress. This happens for temperature cycles and more on the supply rings.
Slots are used to satisly the maximum wire density technology rules. SO by using slots you can control the wire densisty and meet the requirements
Hi, What is the general rule to fill in the dummy to pass the pattern density requirement? For places where there are AC signals I generally don't put any dummy pattern in 10um distance whereas for DC signals I don't take such precaution. Is this a good rule? Thanks :)
There is the "Industrial, Scientific, and Medicine" part of the rules. These may have higher limits if your device qualifies. The other problem you face is the safety laws about microwave power density near humans. In general, if this is a short term academic type experiment the government will not bother what you do in the ISM band. It is
I'd like to know if you do tiling for your analog blocks to meet the metal density rules. If so, how will the filled metal patterns affect the circuit performance and what shall I pay attention to that? In my opinion, I prefer to no metal filling over the poly gate and diffusion area of the matched devices in a sensitive design. And don't cover
Can someone know or suggest right routing grids for routing 0.65mm and 0.5mm pitch smd components, also know via hole diameter for this components. With a 1.27mm pitch no problem for routing with 8mils trace and 5mil grid, but at the low picht, wich routing strategy are best, especially in dense board ? Please reply, skywalker.
Hi, M1 width is the smallest one since it's going to limit your transistor density and it is used for intra-cell routing. The upper one, in general it is used for global power distribution and is thinker than the others, therefore, you cannot achieve smaller width. In the middle the minimum width is fixed by your litho system capabilities.