Bondable glass and low auto-fluorescence article and method of making it
The present disclosure relates to glass articles, a method of making the glass articles, and uses of the glass articles. The glass article has a UV-transmittance of more than 90% at 350 nm and at 500 nm and a total amount of Si 2 , B 2 O 3 and Al 2 O 3 of at least 75 mol %. The article is preferably used in the fields of biotechnology, MEMS, CIS, MEMS-like pressure sensor, display, micro array, electronic devices, microfluidics, semiconductor, high precision equipment, camera imaging, display technologies, sensor/semicon, electronic devices, home appliance, diagnostic product, and/or medical device.
1. A glass article with Li + -activatable bonding properties, comprising:
a UV-transmittance of more than 90% at 350 nm and at 500 nm;
a lithium activatable bonding strength to silicon (LABS) of at least 1.1 MPa;
a total amount of SiO 2 , B 2 O 3 and Al 2 O 3 of at least 75 mol %;
a proportion of Li 2 O that is less than 0.01 mol %;
a molar proportion x Si4+ of Si 4+ ,
a molar proportion x B3+ of B 3+ ; and
a molar proportion x Al3+ of Al 3+ ,
wherein the molar proportions x Si4+ , x B3+ , and x Al3+ are present in accordance with the following ratios:
i
.
x
Si
4
+
x
B
3
+
+
x
A
13
+
≥
2.
,
and
x
Si
4
+
x
B
3
+
+
x
A
13
+
≤
8.
;
and
ii
.
x
B
3
+
x
A
13
+
≥
0.5
.
2. The glass article according to claim 1 , wherein the total amount of SiO 2 , B 2 O 3 and Al 2 O 3 is at least 90 mol %, and wherein the molar proportion x Si4+ of Si 4+ , the molar proportion x B3+ of B 3+ and the molar proportion x Al3+ of Al 3+ are present in accordance with the following ratios:
i
.
x
Si
4
+
x
B
3
+
+
x
A
13
+
≥
3.
,
and
x
Si
4
+
x
B
3
+
+
x
A
13
+
≤
8.
;
and
ii
.
x
B
3
+
x
A
13
+
≥
1.5
.
3. The glass article according to claim 1 , having an R a surface roughness of less than 2 nm.
4. The glass article according to claim 1 , having at least one fire-polished surface.
5. The glass article according to claim 1 , having a total thickness variation of not more than 10 μm.
6. The glass article according to claim 1 , having a Warp of not more than 50 μm.
7. The glass article according to claim 1 , having a coefficient of thermal expansion (CTE, 20 to 300° C.) of from 1 to 10 ppm/K.
8. The glass article according to claim 1 , wherein the glass of the glass article has a working temperature T 4 , and an upper crystallization temperature T OEG , wherein the difference T 4 −T OEG is more than 50 K, wherein working temperature T 4 is from 1000° C. to 1500° C., and the upper crystallization temperature T OEG is from 900° C. to 1300° C.
9. The glass article according to claim 1 , wherein the glass of the glass article has a luminous transmittance T D65 at 0.5 mm thickness of more than 91% and/or less than 91.7%.
10. The glass article according to claim 1 , wherein the glass of the glass article has a UV cutting edge at 1 mm thickness of lower than 300 nm.
11. The glass article according to claim 1 , wherein the glass of the glass article has an autofluorescence emission/excitation intensity ratio at 488 nm of less than 1%.
12. The glass article according to claim 1 , wherein the glass article is a glass wafer or glass sheet, having a width, a length, and a thickness, wherein width and length are each independently at least 10 mm, and the thickness is not more than 1.5 mm.
13. The glass article according to claim 1 , further comprising, after lithium enrichment, at least one surface that is a lithium-enriched surface layer, the glass article having a lithium proportion Li surface in the at least one lithium enriched surface layer, and a bulk lithium proportion Li bulk ,
wherein
Li
surface
[
mol
%
]
Li
bulk
[
mol
%
]
≥
5
,
wherein the lithium-enriched layer has a depth of layer (DoL) of 0.01 to 200 μm.
14. The glass article according to claim 1 , wherein the glass article is bonded to a semiconductor wafer with a bonding strength of at least 1 MPa.