Silicon microchannel plate devices with smooth pores and precise dimensions
A method of fabricating a microchannel plate includes forming a plurality of pores in a silicon substrate. The plurality of pores is oxidized, thereby consuming silicon at surfaces of the plurality of pores and forming a silicon dioxide layer over the plurality of pores. At least a portion of the silicon dioxide layer is stripped, which reduces a surface roughness of the plurality of pores. A semiconducting layer can be deposited onto the surface of the silicon dioxide layer. The semiconducting layer is then oxidized, thereby consuming at least some of the polysilicon or amorphous silicon layer and forming an insulating layer. Resistive and secondary electron emissive layers are then deposited on the insulating layer by atomic layer deposition.
1. A method of fabricating a silicon microchannel plate, the method comprising:
a. forming a plurality of pores in a silicon substrate;
b. oxidizing the plurality of pores, thereby consuming silicon at surfaces of the plurality of pores and forming a silicon dioxide layer over the plurality of pores;
c. stripping at least a portion of the silicon dioxide layer, thereby reducing a surface roughness of the plurality of pores;
d. depositing a film on a surface of the silicon dioxide layer; and
e. depositing resistive and secondary electron emissive layers on the deposited film.
2. The method of claim 1 wherein the plurality of pores are formed by at least one of reactive ion etching, reactive ion beam etching, and electrochemical etching.
3. The method of claim 1 wherein the deposited film on the surface of the silicon dioxide layer comprises a semiconducting film which is thermally oxidized to produce an insulating film.
4. The method of claim 1 wherein the deposited film on the surface of the silicon dioxide layer comprises an oxide of at least one element selected from of the group consisting of Al, Si, Zr, Hf, Ta, and Ti.
5. The method of claim 1 wherein the deposited film on the surface of the silicon dioxide layer comprises a nitride of at least one element selected from of the group consisting of Al, Si, Zr, Hf, Ta, and Ti.
6. The method of claim 1 wherein the emissive layer comprises an oxide of at least one element selected from of the group consisting of Al, Si, Mg, Sn, Ba, Ca, Sr, Sc, Y, La, Zr, Hf, Ta, Ti, V, Cs, B, Nb, Be, and Cr.
7. The method of claim 1 wherein the emissive layer comprises a nitride of at least one element selected of the group consisting of Al, Si, Mg, Sn, Ba, Ca, Sr, Sc, Y, La, Zr, Hf, Ta, Ti, V, Cs, B, Nb, Be, and Cr.
8. The method of claim 1 wherein the depositing the resistive layer on the oxide layer by atomic layer deposition comprises adjusting process parameters to achieve a desired current that replaces emitted electrons during operation.
9. The method of claim 1 wherein the depositing the secondary electron emissive layers on the oxide layer by atomic layer deposition comprises adjusting process parameters to maximize secondary electron efficiency.
10. The method of claim 1 wherein the depositing the resistive and secondary electron emissive layers on the deposited film by atomic layer deposition comprises depositing resistive and secondary electron emissive layers that improve lifetime of the microchannel plate.
11. The method of claim 1 wherein the deposited film on the surface of the silicon dioxide layer is deposited to achieve a desired sidewall shape.
12. The method of claim 1 wherein the depositing the resistive and the secondary electron emissive layers on the film comprises depositing the resistive and the secondary electron emissive layers on the film by atomic layer deposition.