1. An imaging lens system with two lenses, along an optical axis from an object side to an image side, comprising:
an aperture stop;
a first lens having positive refractive power and being a plano-convex lens with a convex surface on the image side; and
a second lens having negative refractive power and being a meniscus lens with a concave surface on the object side and a convex surface on the image side.
2. The system as claimed in claim 1, wherein the imaging lens system with two lenses satisfies the equation:
0.49\u2266BFLTL\u22660.53
wherein BFL is back focal length of the imaging lens system, and TL is distance from the aperture stop to an image plane.
3. The system as claimed in claim 1, wherein the imaging lens system with two lenses satisfies the equation:
65\xb0\u22662\u03c9\u226680\xb0
wherein 2\u03c9 is maximum field angle.
4. The system as claimed in claim 1, wherein the image side of the first lens is aspherical surface.
5. The system as claimed in claim 1, wherein both the convex surface and the concave surface of the second lens are aspherical surfaces.
6. The system as claimed in claim 1, wherein both the first lens and the second lens are made from plastic.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A method of forming a memory device, comprising:
providing a bottom electrode;
forming a memory layer on the bottom electrode including a nitrogen-containing metal oxide; and
forming a top electrode over the nitrogen-containing metal oxide.
2. The method of claim 1, wherein the bottom electrode comprises a transition metal and the nitrogen-containing metal oxide comprises an oxynitride of the transition metal.
3. The method of claim 1, wherein the memory layer includes a first layer of metal oxide, and a second layer including the nitrogen-containing metal oxide.
4. The method of claim 1, wherein the nitrogen-containing metal oxide is formed by thermal oxidation in a nitrogen-containing chamber.
5. The method of claim 1, wherein the bottom electrode comprises a metal having a metal surface, and includes forming the memory layer by oxidizing the metal surface to form a metal oxide over the metal, and exposing the metal oxide to a reaction gas comprising nitrogen to form the nitrogen-containing metal oxide.
6. The method of claim 5, wherein the metal oxide is formed by thermal oxidation of the metal surface.
7. The method of claim 6, said thermal oxidation including a first rapid thermal process using oxygen in a reaction chamber.
8. The method of claim 7, wherein exposing the metal oxide to a reaction gas comprising nitrogen includes a second rapid thermal process, the second rapid thermal process continuing from a temperature hold step of the first rapid thermal process in the reaction chamber using oxygen and nitrogen as the reaction gas to form said nitrogen-containing metal oxide.
9. The method of claim 8, the first rapid thermal process and the second rapid thermal process each including a reaction hold temperature ranging from about 470 degrees Celsius to about 800 degrees Celsius.
10. The method of claim 8, wherein the first rapid thermal process and the second rapid thermal process each include a reaction hold temperature ranging from about 470 degrees Celsius to about 480 degrees Celsius.
11. The method of claim 8, the first rapid thermal process and the second rapid thermal process each including a reaction pressure ranging from about 100 torr to about 1000 torr.
12. The method of claim 8, wherein the reaction gas comprises nitrogen and oxygen provided at a ratio of nitrogen flow rate to oxygen flow rate in a range from 1:8 to about 1:1.
13. The method of claim 8, wherein a ratio of reaction time for the first rapid thermal process to the reaction time for the second rapid thermal process is about 1:2.
14. The method of claim 1, wherein forming the bottom electrode includes:
providing an insulating material;
forming an opening in the insulator material;
lining the opening with a diffusion barrier layer;
depositing the metal over the diffusion barrier in the opening for a bottom electrode.
15. A resistive memory device, comprising:
a bottom electrode;
a memory layer on the bottom electrode including a nitrogen-containing metal oxide; and
a top electrode over the nitrogen-containing metal oxide.
16. The device of claim 15, wherein the bottom electrode comprises a transition metal and the nitrogen containing metal oxide comprises an oxynitride of the transition metal.
17. The device of claim 16, wherein the transition metal is tungsten.
18. The device of claim 15, wherein the memory layer includes a first layer of metal oxide, and a second layer including the nitrogen-containing metal oxide.
19. The device of claim 15 wherein the bottom electrode comprises a metal having a metal surface, and the metal oxide comprises an oxide of the metal at the metal surface.
20. A resistive memory device, comprising:
a bottom electrode comprising a transition metal having a metal surface;
a memory layer on the bottom electrode including a layer of an oxide of the transition metal, and a layer of a nitrogen-containing oxide of the transition metal, and a top electrode over the nitrogen-containing oxide of the transition metal.
21. The device of claim 20, wherein the transition metal is tungsten.