@@ -27,13 +27,13 @@ Based on the metrics of these devices, the following can be inferred for a hypot
Optical power: 70nW/pixel
Pixel pitch: 2.5um
Wavelength: 405um
WPE: 2.7%
WPE: 9% (full space)
3. Wavelength, coherence, intensity and uniformity
Based on the information above, it can be inferred that the LED layer stack of JBD5UM720P-UVA is capable of emitting at 405nm, to which HPR504 is sensitive. Since the source is composed of individual pixels instead of a single source with a photomask, the illumination will be inherently incoherent. Its effects on projection is to be assessed. Uniformity can be ensured, as the display accepts grayscale image.
The intensity at the display is 70nW/pixel for 5.25um2 pixels, that yields 1300mW/cm2. After 5:1 reduction and consideration of 5% will pass trough the optics, this is 1625mW/cm2, sufficient to expose HPR504 in 150ms.
The intensity at the display is 70nW/pixel for 6.25um2 pixels, that yields 1092mW/cm2. After 5:1 reduction and consideration of 5% will pass trough the optics, this is 1365mW/cm2, sufficient to expose HPR504 in 177ms.
4. Resolution, display size, defect density
...
...
@@ -48,7 +48,7 @@ Since the pixel pitch is the half of the MFS and both brightfield and darkfield
Since adoption of LS1U and further LS nodes at commercially viable production scale (i.e. outside of R&D labs) is paramount for reaching the goal of the Libresilicon project (providing really affordable near-single-quantity custom IC production for SMEs, startups, and last but not least, individuals), and the strongest blocking point in such adoption is the cost of obtaining and operating maskless photolithography equipment (all other steps require standard equipment, and easily transferable recipes are published by the project), I recommend to implement the image source unit in LS's maskless stepper "in the form of a glass mask", that is, in such way that its mechanical and optical interface is compatible with existing steppers. For example, the imaging unit may rest on the surface of a 5-inch rectangular glass substrate, with its sides chrome-plated and patterned with alignment marks compatible with ASML steppers, with a UV sensor at the backside is used as a gating input for the display, allowing the unit to be dropped into an ASML (or whatever other brand) stepper without requiring time-consuming, money-burning, warranty-voiding modifications to the adopting fab's existing stepper itself.
Technical problems to be solved with this arrangement are:
a) The imaging unit is expected to generate considerable amount of heat (6.25cm2 with 1300mW/cm2 intensity output and 2.7% WPE is approx. 300W power consumption, most of which is dissipated), resulting in considerable thermal expansion, that needs to be managed (cooling, or using low-LCTE materials).
a) The imaging unit is expected to generate considerable amount of heat (6.25cm2 with 1092mW/cm2 intensity output and 9% WPE is approx. 76W power consumption, most of which is dissipated), resulting in considerable thermal expansion, that needs to be managed (cooling, or using low-LCTE materials).
b) Power supply and data connections need to be implemented without jeopardizing mechanical compatibility.
