Will equipment need to be standardized to take 3D integration with
TSVs to volume production? If so, who will determine what these
standards should be, and how will it affect equipment suppliers who
have already invested in developing equipment for 3D processes? Paul - since you're the equipment guy on the panel, perhaps you'd like to start this off.
Regarding #1
Well, I recently had a conversation with Steve Dwyer of EV Group, who cited an example of how equipment standards are already requiring alteration in the bonding environment from the handling aspect. He said standards currently call for a robot to pick up and return a wafer fto and from the same slot in the FOUP, but with wafer bonding processes, you're picking up two wafers, and finishing up with a bonded pair, essentially leaving an empty slot, there by violating an established industry standard.
If something this basic needs to be standardized but hasn't been yet, doesn't it have repercussions on equipment manufacturers who are already rolling out tools?
For handling, mini environment and fab automation we are already following all established 300mm standards. The 300mm specific standards were (in contrast to 200mm platforms) very useful to accelerate equipment architecture designs between us suppliers / OEMs and customers. We see good signs that this will be the same for future 450mm tools.
In the long run I see also a need for wafer related standards. I'm thinking about compatible wafers coming from different fabs to an OSAT for stacking. We are optimizing equipment to support this compatibility requirement - for example by adjusting linear scaling errors between two wafers to achieve optimum alignment.
When it comes to process or alignment modules definitely there will be proprietary designs - even in the long run.
I agree Paul, there will need to be a whole new set of standards related to the wafers. We currently have to maintain as many as 5 different alignment marks depending on the assembly flow and the fabs involved.
There is a saying, "The nice thing about standards is there are so many to choose from." This seems to apply to how we need to deal with multiple sourced and processed 3D wafers.
SEMI 1.15 comes to mind - wafer diameter, bevel edge, notch and thickness. All these are affected by the bonding, trimming and thinning processes. In addition, E47.1 (FOUPs), M31 (FOSBs) and T7 (wafer identification) are impacted. We need to identify all the ones affected and get to work on modifications.
Regarding #5
It seems to me that setting standards is an evolutionary process, so it seems that modifying existing ones, at least with regard to equipment, is a good place to start.
Paul - we discussed this a bit in our podcast interview. Would you say that for equipment manufacturers, when designing tools for emerging technologies, there is an awareness of building in adaptability to accomodate evolving standards?