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Technology Stocks : Advanced Micro Devices - Moderated (AMD)
AMD 249.66+7.6%Jan 21 3:59 PM EST
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To: pgerassi who wrote (252933)6/6/2008 8:08:29 PM
From: misenRead Replies (1) of 275872
 
Pete:

I am quite familiar with semiconductor processing -- I do not need the "information" in your post explained to me.

I was looking for a yes-or-no answer.

Do you think any semiconductor process anywhere has 200+ passes through a stepper/scanner to expose photoresist?

Do you think any production semiconductor process anywhere has 100+ passes through a stepper scanner to expose photoresist?


Perhaps we are talking about two different things. These things happen when discussions become illustrative. Some terms I use are non standard looking as an outsider.

Perhaps you should use standard terms then. Or admit that perhaps you don't understand things correctly.


The mask set I refer to is to make one scan pass of the wafer. So a SESP process uses one scan to make a step in the process. One metal layer must use at least 4 scans to fabricate, one for the vias, one for the insulating layer, one for the interconnect metal and one for the insulation between the metal lines. AMD's 65nm process uses 11 metal layers thus there are 44 scans at a minimum assuming SESP just for that.

Putting aside any discussion of double patterning, you are off by a factor of two here. For a modern process, using damascene copper metallization, it takes only two mask layers, metal and via. There is no patterning for insulating layer and there is no patterning for insulation between the metal lines. Just the layer to define the trench that the damascene metal is deposited in, and a layer to define the via that connects metal layers.

more incorrect info cut

So if all of the layers had to use DEDP, we would have 200 scans required. The thing is that some layers are used to remove previous layers to be replaced by other materials. The gate first MG process that Intel uses does such a thing. As does adding strain. FOr IBM/AMD/etal's process with dual strain, the same layer has to have more than two scans to accomplish. So its quite possible for a very complex cutting edge process to have 200+ scans needed with DEDP.

Pete, a double patterning scheme is only used for the critical layers in a process. This is a small fraction of the overall number of layers. There is no way that any near-term process will have all layers using double patterning.

So a 200+ layer (scan) production process may not be as far away as you think.

It is so far away that it is ludicrous to even suggest it as a possibility.


BTW, what do you call a single scan relative to a given process?

I call it a mask layer or a masking step.

Misen
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