Process for producing flexible organic-inorganic laminates

Abstract

The present invention is in the field of processes for producing flexible organic-inorganic laminates as well as barrier films comprising flexible organic-inorganic laminates by atomic layer deposition. In particular the present invention relates to a process for producing a laminate comprising more than once the sequence comprising: (a) depositing an inorganic layer by performing 4 to 150 cycles of an atomic layer deposition process, and (b) depositing an organic layer comprising sulfur by a molecular layer deposition process.

Claims

1. A laminate comprising, more than once, a sequence comprising (a) an inorganic layer of a (semi)metal oxide, elemental (semi)metal or (semi)metal nitride having a thickness of 0.4 to 3 nm and (b) an organic layer consisting of S and one or more elements selected from the group consisting of C, H, O, N, Se and P, wherein the laminate has a water vapor transmission rate (WVTR) of less than 10.sup.−2 g/m.sup.2d when dried at 70% relative humidity at 70° C. for 480 h and bent with a radius of 1.5 cm.

2. The laminate according to claim 1 wherein the sulfur of the organic layer is in an oxidation state −2, −1 or 0.

3. The laminate according to claim 1, wherein the inorganic layer comprises AlO.sub.x(OH).sub.y, wherein 0≤x≤1.5; 0≤y≤3 and 2x+y=3.

4. The laminate according to claim 1, comprising at least 30 of the inorganic layers (a) alternating with at least 30 of the organic layers (b).

5. A barrier film comprising the laminate according to claim 1.

6. The barrier film according to claim 5 wherein the barrier film further comprises a polymeric substrate.

7. The barrier film according to claim 5 wherein the barrier film further comprises a planarization layer.

8. A method of encapsulating, packaging, or passivating an object, the method comprising: encapsulating, packaging, or passivating the object with the barrier film according to claim 5.

9. An electronic device comprising the barrier film according to claim 5.

10. The barrier film according to claim 5, which has a WVTR of less than 10.sup.−5 g/m.sup.2d when dried at 70% relative humidity at 70° C. for 480 h.

11. The barrier film according to claim 5, which has a WVTR of less than 10.sup.−2 g/m.sup.2d when dried at 70% relative humidity at 70° C. for 480 h and bent with a radius of 1.5 cm.

12. The barrier film according to claim 5, which, when dried at 70% relative humidity at 70°C for 480 h and bent with a radius of 1.5 cm, has a WVTR that is not more than 1000 times higher than a WVTR of the barrier film when dried at 70% relative humidity at 70° C. for 480 h and not bent.

13. A process for producing the laminate according to claim 1, the process comprising, more than once, a sequence comprising: (a) depositing an inorganic layer of a (semi)metal oxide, elemental (semi)metal or semi(metal) nitride by performing 4 to 150 cycles of an atomic layer deposition (ALD) process, and (b) depositing an organic layer consisting of S and one or more elements selected from the group consisting of C, H, O, N, Se and P by a molecular layer deposition process, wherein the ALD process comprises the decomposition of a (semi)metal compound to the (semi)metal oxide, elemental (semi)metal or (semi)metal nitride after the (semi)metal compound has been deposited.

14. The process according to claim 13, wherein the molecular layer deposition process comprises depositing the organic layer with a thiol.

15. The process according to claim 13, wherein the molecular layer deposition process comprises depositing the organic layer with a dithiol.

16. The process according to claim 13, wherein the molecular layer deposition process comprises depositing the organic layer with an aromatic thiol.

17. The process according to claim 13, wherein the atomic layer deposition process comprises depositing the inorganic layer with an Al-containing compound.

18. The process according to claim 13, wherein the process comprises performing the sequence comprising (a) and (b) at least 30 times.

19. A laminate comprising, more than once, a sequence comprising: (a) an inorganic layer of a (semi)metal oxide, elemental (semi)metal or (semi)metal nitride having a thickness of 0.4 to 3 nm and (b) an organic layer consisting of S and one or more elements selected from the group consisting of C, H, O, N, Se and P obtained with an organic thiol comprising one or more hydroxyl groups.

20. The laminate according to claim 19, wherein the laminate has a water vapor transmission rate (WVTR) of less than 10.sup.−2 g/m.sup.2d when dried at 70% relative humidity at 70° C. for 480 h and bent with a radius of 1.5 cm.

Description

EXAMPLES

Example 1 (Inventive)

(1) A barrier film was made by using a PET substrate. The PET substrate had a size of 2.5×2.5 cm.sup.2, a thickness of 100 μm, and a density of 1.4 g/cm.sup.3. The PET substrate was cleaned by rinsing with deionized water, acetone and ethanol followed by a 30 min O.sub.2 plasma treatment with a plasma power of 100 W. Afterwards the PET substrate was degassed within a vacuum chamber for 30 min until the pressure reached 5.Math.10.sup.−5 mbar. The vacuum chamber including the PET substrate was heated to 80° C. Trimethylaluminum (TMA) in the gaseous state was introduced into the vacuum chamber by opening a valve to a side chamber containing TMA in liquid form for 2 s, then the vacuum chamber was evacuated again to reach 5.Math.10.sup.−5 mbar for 15 s.

(2) After this, water in the gaseous state was introduced into the vacuum chamber for 2 s after which the vacuum chamber was again evacuated for 38 s. This sequence was performed six times. Then TMA was introduced into the vacuum chamber as describe above for 2 s, the vacuum chamber was evacuated for 15 s whereupon 4-mercaptophenol (4MP) was introduced into the vacuum chamber by opening a valve to a chamber containing liquid 4MP at 85° C. for 8 s after which the vacuum chamber was evacuated for 200 to 300 s.

(3) The above described sequence is denoted by [[TMA-H.sub.2O].sub.6-TMA-4MP]. This sequence was consecutively performed 250 times.

(4) The same laminate was prepared on a silicon wafer. This wafer was fractured and subject to scanning electron microscopy. The thus obtained image is depicted in FIG. 1. The thickness of the laminate was estimated from the image to be 301 nm.

Example 2.1 (Inventive)

(5) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.8-TMA-4MP] was consecutively performed 140 times.

Example 2.2 (Inventive)

(6) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.8-TMA-4MP] was consecutively performed 220 times.

(7) The same laminate was prepared on a silicon wafer. This wafer was fractured and subject to scanning electron microscopy. The thus obtained image is depicted in FIG. 2. The thickness of the laminate was estimated from the image to be 316 nm.

Example 2.3 (Inventive)

(8) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.8-TMA-4MP] was consecutively performed 280 times.

Example 3 (Inventive)

(9) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.13-TMA-4MP] was consecutively performed 150 times.

(10) The same laminate was prepared on a silicon wafer. This wafer was fractured and subject to scanning electron microscopy. The thus obtained image is depicted in FIG. 3. The thickness of the laminate was estimated from the image to be 290 nm.

(11) FIGS. 4a and 4b show the Raman absorption spectrum of this laminate prepared on a silicon wafer, wherein FIG. 4a shows the whole spectrum and FIG. 4b shows the spectrum from 900 to 300 cm.sup.−1.

Example 4 (Inventive)

(12) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.25-TMA-4MP] was consecutively performed 90 times.

(13) The same laminate was prepared on a silicon wafer. This wafer was fractured and subject to scanning electron microscopy. The thus obtained image is depicted in FIG. 5. The thickness of the laminate was estimated from the image to be 290 nm.

Example 5 (Comparative)

(14) A barrier film was made as in example 1 wherein a sequence [[TMA-H.sub.2O].sub.3-TMA-4MP] was consecutively performed 380 times.

(15) The same laminate was prepared on a silicon wafer. This wafer was fractured and subject to scanning electron microscopy. The thus obtained image is depicted in FIG. 6. The thickness of the laminate was estimated from the image to be 338 nm.

Example 6 (Comparative)

(16) A barrier film was made by alternatingly exposing a PET substrate to TMA and H.sub.2O under the conditions described in example 1 for 500 times.

Example 7 (Comparative)

(17) A barrier film was made by alternatingly exposing a PET substrate to TMA and H.sub.2O under the conditions described in example 1 for 250 times.

Example 8 (Inventive)

(18) A barrier film was made as in example 2 wherein instead of 4MP 4-mercaptobenzylic alcohol (4MBA) was used which was kept at 90° C.

Example 9 (Inventive)

(19) A barrier film was made as in example 3 wherein instead of 4MP 4MBA was used which was kept at 90° C.

(20) Testing of the Barrier Films

(21) The water vapor transmission rates (WVTR) of the barrier films prepared on PET substrates were tested by evaporating 144 dots of Ca with a thickness of 350 nm and a size of 10×10 μm.sup.2 on each film at 1.3.Math.10.sup.−7 mbar. On top of the Ca dots another laminate was made as described in the respective examples. The films were then placed inside a drying cabinet with 70% relative humidity at 70° C. for 480 h. The WVTR was calculated by the number of Ca dots which became transparent after this storage procedure as described above.

(22) The barrier film was bent 100 times at a bending radius of 0.5 and 1.5 cm respectively. Afterwards the WVTR was calculated as described above with the difference that the samples were stored for 360 h. The results are summarized in the following table.

(23) TABLE-US-00001 WVTR in g/m.sup.2d before After bending with radius of Example bending 1.5 cm 0.5 cm 1 (inventive)  6 .Math. 10.sup.−5 2.1 (inventive)  2 .Math. 10.sup.−6 2.2 (inventive) <1 .Math. 10.sup.−6 <2 .Math. 10.sup.−6 <3 .Math. 10.sup.−6 2.3 (inventive) <1 .Math. 10.sup.−6 3 (inventive) <1 .Math. 10.sup.−6  2 .Math. 10.sup.−6  7 .Math. 10.sup.−5 4 (inventive) <1 .Math. 10.sup.−6 5 (comparative) >0.1 6 (comparative)  1 .Math. 10.sup.−6 >0.1 >0.1 7 (comparative)  5 .Math. 10.sup.−5 >0.1 >0.1 8 (inventive) <1 .Math. 10.sup.−6 <1 .Math. 10.sup.−6 <1 .Math. 10.sup.−6 9 (inventive) <1 .Math. 10.sup.−6 <1 .Math. 10.sup.−6 <1 .Math. 10.sup.−6

(24) In addition, the film obtained in example 8 was bent 1000 times at a bending radius of 0.5 and 1.5 cm respectively. The WVTR remained under 1.Math.10.sup.−6 g/m.sup.2d.