It is yellow. The reason for this are indeed the frequencies of light.
Although the photoresist used on wafers under process during the litho steps is most sensitive to a certain wavelenght (193 nm for 90 nm feature size, see wikipedia on litho), unindented exposure most be avoided at all costs.
Working under normal light would ruin any wafer with photoresist. Working in total dark would be ideal, but yellow is supposed to be some good compromise between working conditions and process issues.
Allthough the litho part of chip manufactering happens under the yellow light, other parts of a cleanroom normally have normal lightning.
I really do not like the useless opening of new windows when clicking on a link. There isn't even a way to discriminate between links with target="_blank" and those that will just open in the current window/tab.
I have a functioning back-button in the case I'd like to go to the previous page, so no need to keep it open in yet another window.
For some unknown reason most of the online discussion boards seem to function like this.
Mozilla to the rescue! In Mozilla 1.7.x (maybe in different versions as well) you can disable the ability of pages to open in a new window (unless on explicit request - context menu->open in new window). All you have to do is set dom.disable_open_during_load to true and you're fixed.
I remembered about modifying this setting when reading parent's post.
As I was not able to get the hi-jack test to work, having this setting for quite some time, I think making this tweak will also immunify you from the discussed vurnability!
Yes. That is a problem. Mask prices are rising to 100k $ a mask.
But it is not the real issue. What is the showstopper for doing a one-flash image is the lens in the wafer stepper or scanner.
You see, the lens is the most capital part of a stepper/scanner (stepper/scanner would be the camera in the classic photography analogy - which is in itself one of the most capital tools in any fab).
It has an usable field size of around 28 square mm. Way too small to do a wafer at once.
The work around is, of course, to illuminate many small pieces of wafer one by one (such a piece of equipment is called a wafer stepper) or do a stroke of the whole wafer in one contignious scan (a step and scan system or scanner).
While this adds costs to the equipment in general (for a stepper it is really difficult to know where it is projecting its image relative to the wafer - takes lots of interesting engineering) it is way more viable than devising a lens wich works equally well for all regions of something the size of a large pizza.
Slashdot Mirror
Working under normal light would ruin any wafer with photoresist. Working in total dark would be ideal, but yellow is supposed to be some good compromise between working conditions and process issues.
Allthough the litho part of chip manufactering happens under the yellow light, other parts of a cleanroom normally have normal lightning.
I have a functioning back-button in the case I'd like to go to the previous page, so no need to keep it open in yet another window. For some unknown reason most of the online discussion boards seem to function like this.
Mozilla to the rescue! In Mozilla 1.7.x (maybe in different versions as well) you can disable the ability of pages to open in a new window (unless on explicit request - context menu->open in new window). All you have to do is set dom.disable_open_during_load to true and you're fixed.
I remembered about modifying this setting when reading parent's post. As I was not able to get the hi-jack test to work, having this setting for quite some time, I think making this tweak will also immunify you from the discussed vurnability!
Yes. That is a problem. Mask prices are rising to 100k $ a mask.
/me develops control software for wafer steppers
But it is not the real issue. What is the showstopper for doing a one-flash image is the lens in the wafer stepper or scanner.
You see, the lens is the most capital part of a stepper/scanner (stepper/scanner would be the camera in the classic photography analogy - which is in itself one of the most capital tools in any fab).
It has an usable field size of around 28 square mm. Way too small to do a wafer at once.
The work around is, of course, to illuminate many small pieces of wafer one by one (such a piece of equipment is called a wafer stepper) or do a stroke of the whole wafer in one contignious scan (a step and scan system or scanner). While this adds costs to the equipment in general (for a stepper it is really difficult to know where it is projecting its image relative to the wafer - takes lots of interesting engineering) it is way more viable than devising a lens wich works equally well for all regions of something the size of a large pizza.