UV reflective mirrors for display fabrication
An apparatus which includes an ultraviolet laser and at least one reflective mirror having a substrate which is made from beryllium, an aluminum metal matrix, or silicon carbide. The at least one mirror is adapted to reflect a laser beam generated from the ultraviolet laser, which can then be used on a silicon film used in the production of an electronic display. The laser beam can be used to anneal the silicon film, or in a laser lift-off process for separating the silicon film from a temporary substrate upon which the silicon film was mounted.
1. An apparatus comprising:
an ultraviolet laser; and
at least one reflective mirror adapted to reflect a laser beam generated from the ultraviolet laser;
wherein the at least one reflective mirror comprises a mirror substrate,
wherein the mirror substrate is made from silicon carbide or an aluminum metal matrix composite, and has:
(i) an optical Figure of Merit (FoM) resonant frequency value of at least 6 relative to a fused-quartz substrate;
(ii) an optical FoM self-weight deflection value of less than 0.030 relative to a fused-quartz substrate;
(iii) an optical FoM steady-state thermal distortion coefficient value of less than 0.350 relative to a fused-quartz substrate; and
(iv) an optical FoM transient thermal distortion coefficient value of less than 0.600 relative to a fused-quartz substrate.
2. The apparatus of claim 1 , wherein the mirror substrate is made of an aluminum metal matrix composite of an aluminum alloy and one or more reinforcing particles.
3. The apparatus of claim 2 , wherein the one or more reinforcing particles includes at least one ceramic material selected from the group consisting of carbides, oxides, silicides, borides, and nitrides.
4. The apparatus of claim 2 , wherein the one or more reinforcing particles includes silicon carbide.
5. The apparatus of claim 2 , wherein the metal matrix composite comprises a 6061, 6063, 6082, 2009, 2618 or 2124 aluminum alloy reinforced with from about 15 vol % to about 40 vol % of silicon carbide.
6. The apparatus of claim 1 , an ultraviolet reflective coating deposited upon the mirror substrate, wherein the ultraviolet reflective coating is a layer made from a combination of hafnium dioxide (HfO 2 ) and silicon dioxide (SiO 2 ), or wherein the ultraviolet reflective coating is formed from alternating layers of (i) a coating formed from aluminum and hafnium oxide and (ii) a coating formed from aluminum and silicon dioxide.
7. A method of making an electronic part, comprising:
receiving an ultraviolet laser apparatus comprising an ultraviolet laser and at least one reflective mirror comprising a mirror substrate;
generating a laser beam with the ultraviolet laser; and
reflecting the laser beam with the at least one reflective mirror toward a precursor film to produce the electronic part;
wherein the mirror substrate is made from silicon carbide or an aluminum metal matrix composite, and has:
(i) an optical Figure of Merit (FoM) resonant frequency value of at least 6 relative to a fused-quartz substrate;
(ii) an optical FoM self-weight deflection value of less than 0.030 relative to a fused-quartz substrate;
(iii) an optical FoM steady-state thermal distortion coefficient value of less than 0.350 relative to a fused-quartz substrate; and
(iv) an optical FoM transient thermal distortion coefficient value of less than 0.600 relative to a fused-quartz substrate.
8. The method of claim 7 , wherein the precursor film is an amorphous film.
9. The method of claim 8 , wherein the laser beam is reflected directly upon the precursor film to induce crystallization of the amorphous film.
10. The method of claim 8 , wherein the precursor film is mounted upon a temporary substrate, and the laser beam is reflected through the temporary substrate onto the precursor film to separate the precursor film from the temporary substrate.
11. The method of claim 7 , wherein the electronic part is used in an organic light-emitting diode (OLED) display or a low-temperature polycrystalline silicon liquid crystal display (LTPS LCD).
12. An ultraviolet reflective mirror, comprising:
a mirror substrate; and
an ultraviolet reflective coating deposited upon a front surface of the mirror substrate;
wherein the mirror substrate is made from silicon carbide or an aluminum metal matrix composite, and has:
(i) an optical Figure of Merit (FoM) resonant frequency value of at least 6 relative to a fused-quartz substrate;
(ii) an optical FoM self-weight deflection value of less than 0.030 relative to a fused-quartz substrate;
(iii) an optical FoM steady-state thermal distortion coefficient value of less than 0.350 relative to a fused-quartz substrate; and
(iv) an optical FoM transient thermal distortion coefficient value of less than 0.600 relative to a fused-quartz substrate.
13. The mirror of claim 12 , wherein a rear surface of the mirror substrate includes ribs for strengthening the mirror.