claims in describing the specification should be construed to be a single layer of material the board air when it included that it could be multiple layers of material the nd claim construction issue is construction of the term forming a st dielectric layer on the surface and exposing a portion of the surface of the substrate and really that's a question of what the surface of the substrate is and the key point there is that the surface is that of the silicon wafer and not any intervening layer as explained in the prosecution suggest i tend to think you might be right that that construction is a little wonky but even if it is doesn't really matter i would submit it does your honor because the substrate the material t but so you wouldn't agree for instance that if we were to find that it that two different aspects of the substrate to constitute one substrate i guess is that the go wherever you want to go resolving questions turning back to the st issue and so the the invention described in the twenty seven and ultimately claim is an improved method of e in forming a contact for semiconductor processes and one aspect of an important aspect of it is that it reduces the number of edges to which the substrate is exposed thus reducing damage to the and the specification uniformly describes a single layer or a single material as the layer for each tile later where there is no discussion specification of any combination of materials being or more than one but we think that we fit within the exception as described for example in the northern case that we cited in our brief but they take the argument that your friend on the other side is certain to stand up and make as i understand from their briefs is that right the board construed as including the possibility of of you know two layers when you call them sub layers and with you call the two layers what do we do with the fact that one of the ways they got their last through the expert testimony that we have to defer to right now the expert testimony is extrinsic evidence that you rely solely on extremes we have and so the expert testimony is not an explanation of anything that's in the o t seven patent but it's it's the expert issue here which has a completely different structure and as a gate structure where the claim in that compound specifically says a layer comprised of a st and then you describe several layers of dielectric material so that certainly there are contexts where in the art where dielectric layer can have multiple layers but in the context of the o t seven in particular the intrinsic record of the o t seven that and the only discussion is  single material and we think that should control and we think that the board erred when it went well but i don't really read his expertize money quite as year only we need doesn't say that oh no is the only reason that one of gleaned from this that i would i would disagree with that only in sense your honor that that there is no reference in his paragraph three at seven you know three and seven you know four of the past and that issue in terms of any specific example of a multiple layer in the o t seven you know he does talk generally and then he supports that by citing to his prior art and then to another promise that he doesn't point  specification or file history and says there's some wiggle room here in the spec that supports my notion that the st dielectric layer can include multiple layers here and so your prior art pro that's defined as a boat nd dielectric light layer within it in a gate and then it recites three specific layers so there's it's not you know there's actual recitation of different layers in the larger context of that claim drafting choice for that particular structure which is different from the structure here is the your if as i understood it you conceded that layer could conceivably be multiple layers but that you're really saying that that this  with a structure that showed a oxide layer between the st dielectric layer and the substrate and at the time the claim is read forming layers on a material the claims were amended to include words substrate and replace that material  history and the full interests of record here you can come away with any conclusion other than that that there was at least a portion on the surface limitation that was i don't know what the clock disclaimed or given away very clearly in connection with that back and forth with the examiner and and when you try to say well maybe you could read that differently but it's pretty logical that you can only read it one way so what do you do with that with the conclusion that perhaps i at least might disagree with your on the surface limitation improperly construed sure your hon it i'm sorry it's so we believe it's irrelevant to the parties dispute that particular claim construction issue because the board made a factual finding i was actually gonna start with the coil my shoe the board made a factual finding here that the  i mean i think that goes to what i commend your your friend on the other side for which is a logical concession which they have to weigh and oh the both construction arguments in order to prevail and i'm saying i think you might win one or at least for me so what does that matter how does that matter right and i don't think it matters as your honour's hinting at so if you actually look at coma and look at the evidence that the that the board looked at on that point and if i could have the court look at the basically the issue with coma is that what is there is a suicide layer is it part of the structure or is it some other layer that's not part of the substrate and here on appendix fifty four the board looked at the testimony of sampson the expert who love it looked at the testimony of promises expert mr material and rejected the testimony of mr monk and you can see that here he said to the extent there is conflicting testimony and i'm reading from a know really even appeal that finding substantial evidence more than supports that finding so we think the board of this court can affirm the coil my ground and if it does that the board's decision should be a farm and unless the court has any questions on why doesn't that matter in terms of determining whether it's a single layer versus this is so the reason it doesn't matter your honor is because the board made a factual finding right because that gets to the point of what in onal is a st dr clear that's claimed right on and said they serve the same purpose of protecting the gate electrodes and source and drain regions and therefore they collectively constitute the st electric layer those are factual findings made by the board based on the evidence and then kind of the difference so you can still have one layer even though the sub blair would actually perform defense functions instead and and have different properties certainly your honor because what could happen is  that's appendix to somebody so so here dr ruth loft looked at not only at the twenty seven patent he looked at homeless as other patents he looked at the prior art and collectively based on all of that he provided his opinion that based on his experience and all of this evidence that a dielectric layer certainly is not limited to a single layer of a single material so a judge or malli and your arms unless you have any other question and i do not want to go to go back to you on the surface issue ok as for a couple minutes ok ok look i'll make it quick on that you know from our perspective the the on the surface they exam meet the exacting standard of clear and unmistakable disclaimer they certainly could have amended the claims to cite in contact with or direct and the terms of we're talking about today on the surface layer these are some of the most normal in this art but that's exactly where the examiner said it is it's obvious or or anticipated if you don't make this change right so it's a yawner i disagree i don't think the examiner went that far you know our issue is as a reasonable competitor notice right there a whole argument on the on the surface as they said look if you look at the prosecution history it's only one page they made an amendment and then we have one page from our perspective looking at this case a court case to the disputes here and sometimes when i see these kinds of issues i like to say that what if we were looking at this in reverse and they were trying to claim that they covered more and they could cover this in direct and it was an infringement issue i'm betting you'd be there that identifies any intrinsic evidence that shows multiple sub layers in the twenty seven pad and all that is is a reference to dependent claims two dollars and three dollars which were cite the specific materials civil side and then the solar side layer is etched off except over the source of the drain so you have a sill a side layer that is formed on top of the substrate and so if the substrate is the silicon wafer then the still a side  something that is formed on top of it and is not part of the substrate if the substrate is silicon late wafer plus chemical reactions in the surface and that's the construction and