Method for manufacturing flat substrates
View Patent ↗For avoiding the metallic inner surface of a PECVD reactor to influence thickness uniformity and quality uniformity of a μc-Si layer ( 19 ) deposited on a large-surface substrate, ( 15 ) before each substrate is single treated at least parts of the addressed wall are precoated with a dielectric layer ( 13 ).
1. A method for manufacturing flat substrates with an extent of at least of 2500 cm 2 and having a Si layer, deposited by means of a PECVD process in a vacuum reactor with a substrate carrier first electrode and spaced therefrom, a gas shower second electrode comprising:
a) generating an RF plasma discharge in a reaction space between said electrodes;
b) depositing on at least a part of the inner surface of said reactor a dielectric precoat;
c) introducing one substrate into said reactor;
d) depositing on a surface of said substrate a dielectric layer;
e) PECVD depositing on said dielectric layer said Si-layer;
f) repeating steps b) to e)for each single substrate to be manufactured, thereby depositing said silicon layer as a microcrystalline silicon layer and to do so selecting said dielectric layer deposited on said surface of said substrate as well as said precoating to allow said silicon layer to grow up as a microcrystalline silicon layer along said substrate.
2. The method of claim 1 comprising providing said reactor with a substrate carrier first electrode and, spaced therefrom, a gas shower second electrode and introducing in step c) said substrate to reside on said first substrate carrier electrode.
3. The method of claim 1 , wherein at least one of depositing on at least a part of the inner surface of said reactor a dielectric precoat and of depositing on a second surface of said substrate a dielectric layer is performed by PECVD processing.
4. The method of claim 1 , wherein step e) comprises plasma activating a gas mixture comprising a silicon-containing gas, a halogen-containing gas, hydrogen.
5. The method of claim 1 , wherein step e) comprises plasma activating a gas or gas mixture comprising a noble gas.
6. The method of claim 1 , wherein at least said surface of said substrate is of glass.
7. The method of claim 1 , wherein at least one of step b) and step d) comprises depositing of at least one of silicon oxide, silicon nitride, silicon oxynitride, fluorinated silicon oxide.
8. The method of claim 1 , wherein step b) comprises depositing silicon nitride.
9. The method of claim 1 , wherein depositing on said dielectric layer a μc-Si layer comprises plasma activating a gas or gas mixture which produces etching and layer growth contributing radicals.
10. The method of claim 9 , wherein said gas or gas mixture comprises SiF 4 .
11. The method of claim 1 , wherein step b) comprises depositing said dielectric precoat with a thickness d for which there is valid:
200 nm≦d≦500 nm.
12. The method of claim 11 , wherein there is valid for said thickness d 200 nm≦d≦400 nm.
13. The method of claim 1 , wherein said step b) comprises depositing said dielectric precoat as a layer of amorphous material structure.
14. The method of claim 1 , wherein a material of said precoat deposited in step b) and of said dielectric layer deposited in step d) are equal.
15. The method of claim 1 for manufacturing thin film transistor display substrates.
16. The method of claim 1 for manufacturing liquid crystal display substrates.
17. The method of claim 1 for manufacturing solar cell substrates.
18. The method of claim 1 for manufacturing organic light-emitting display panels.
19. The method of claim 1 for manufacturing substrates with μc-Si layers as layers of semiconductor devices.
20. The method of claim 1 , further comprising plasma cleaning at least said part of the inner surface of said reactor before performing step b).
21. The method of claim 20 , wherein said cleaning is performed in plasma-activated SF 6 and oxygen.
22. A method for manufacturing substantially flat substrates with an exposed surface having an area of at least of 2500 cm 2 and including a Si layer, deposited by means of a PECVD process in a vacuum reactor with a substrate carrier first electrode and spaced therefrom, a gas shower second electrode comprising:
a) generating an RF plasma discharge in a reaction space between said electrodes;
b) depositing on at least a part of the inner surface of said reactor a dielectric precoat, wherein the at least part of the inner surface on which the dielectric precoat is deposited includes at least a portion of the substrate carrier;
c) subsequent to depositing the dielectric precoat onto at least a portion of the substrate carrier, supporting said substrate on the substrate carrier, wherein substantially an entire periphery of the substrate is separated from the substrate carrier by the dielectric precoat deposited on the substrate carrier;
d) depositing on a surface of said substrate supported by said substrate carrier a dielectric layer;
e) PECVD depositing on said dielectric layer said Si-layer, wherein said Si-layer is a microcrystalline Si-layer.
23. The method according to claim 22 , wherein at least one of the dielectric precoat and the microcrystalline Si-layer is deposited with a thickness uniformity adjacent to an edge of the substrate that deviates from an average thickness by about 7% of the average thickness or less.
24. The method according to claim 22 , wherein the dielectric precoat is deposited over substantially all of the expose surface of the substrate carrier.