What is claimed is:
1. A rolling crutch comprising:
(a) a lightweight metal support shaft, said shaft having a top and a bottom;
(b) a cushioned knee pad mounted to the shaft and extending perpendicularly from the shaft at a position which is comfortable for a user to rest a knee of an injured leg;
(c) a handlebar mounted at the top of the shaft and extending perpendicularly with respect to the shaft at a 90 degree angle with respect to the knee pad;
(d) a rectangular base mounted at the bottom of the shaft and extending perpendicularly from the shaft in the same direction as the cushioned knee pad; and
(c) wheels with a stopping mechanism mounted on each corner of the rectangular base, wherein the stopping mechanism engages upon application of weight downward on the crutch.
2. The rolling crutch of claim 1 wherein the metal support shaft comprises multiple interconnecting hollow metal tubes so that the shaft is adjustable to a selected height.
3. The rolling crutch of claim 1 wherein the base is sized for stair compatibility.
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 for patterning a material layer comprising:
forming a mask layer on the material layer;
forming a first photoresist layer on the mask layer;
performing a first exposure process on the first photoresist layer;
performing a first develop process to remove the exposed first photoresist layer together with a portion of the mask layer exposed by the exposed first photoresist layer to form a first pattern of a first pitch;
removing the first photoresist layer;
forming a second photoresist layer;
performing a second exposure process on the second photoresist layer;
performing a second develop process to remove the exposed second photoresist layer together with a portion of the mask layer exposed by the second photoresist layer to form in the mask layer a second pattern of a second pitch that exposes a portion of the material layer, wherein the second pitch is less than the first pitch;
removing the second photoresist layer;
hardening the mask layer after the second photoresist layer is removed;
forming a third photoresist layer with a third pattern on the portion of the material layer exposed by the second pattern, wherein the third photoresist layer and the second pattern together form a fourth pattern; and
patterning the material layer by using the fourth pattern as an etching mask.
2. The method recited in claim 1, wherein the second pattern is used to form at least one trench in the material layer.
3. The method recited in claim 1, wherein the second pitch is smaller than the optical resolution during each of the first and the second exposure processes.
4. The method recited in claim 1, wherein the mask layer is made of a bottom anti-reflection coating material.
5. The method recited in claim 4, wherein the bottom anti-reflection coating material is dissolved during both of the first and the second develop processed and is not dissolved during the first and the second photoresist layers are removed.
6. A method for patterning a material layer comprising:
forming a mask layer on the material layer;
forming a first photoresist layer on the mask layer;
performing a first exposure process on the first photoresist layer;
performing a first develop process to remove the exposed first photoresist layer together with a portion of the mask layer exposed by the first photoresist layer to form a first pattern of a first pitch;
removing the first photoresist layer;
hardening the mask layer;
forming a second photoresist layer;
performing a second exposure process on the second photoresist layer;
performing a second develop process to remove the exposed second photoresist layer, wherein the remaining second photoresist layer and the mask layer together form a second pattern of a second pitch less than the first pitch; and
patterning the material layer by using the second pattern as a mask.
7. The method recited in claim 6, wherein second pattern is used to form at least one line of the material layer.
8. The method recited in claim 6, wherein the second pitch is smaller than the optical resolution during each of the first and the second exposure processes.
9. The method recited in claim 6, wherein the mask layer is made of a bottom anti-reflection coating material.
10. The method recited in claim 9, wherein the bottom anti-reflection coating material is dissolved during both of the first and the second develop processed and is not dissolved during the first and the second photoresist layers are removed.
11. A method for patterning a material layer, the method comprising:
forming a mask layer on the material layer;
performing a multiple patterning process on the mask layer for transferring at least a first pattern from a first photomask through a first photoresist layer and a second pattern from a second photomask through a second photoresist layer into the mask layer without performing any etching process, wherein the mask layer exposes a portion of the material layer, the mask layer is patterned at the time that the first photoresist layer and the second photoresist layer are developed respectively, and the second photoresist layer is removed after the mask layer is patterned;
hardening the mask layer after the second photoresist layer is removed;
forming a third photoresist layer with a third pattern on the portion of the material layer exposed by the mask layer, wherein the third photoresist layer and the mask layer together form a fourth pattern; and
performing an etching process to pattern the material layer by using the fourth pattern as an etching mask.
12. The method recited in claim 11, wherein the multiple patterning process further comprises:
forming the first photoresist layer on the mask layer;
patterning the first photoresist layer by using the first photomask and developing the first photoresist layer to remove a portion of the first photoresist layer together with a portion of the mask layer exposed by the first photoresist layer;
removing the first photoresist layer;
forming a second photoresist layer on the mask layer having the first pattern therein;
patterning the second photoresist layer by using the second photomask and developing the second photoresist layer to remove a portion of the second photoresist layer together with a portion of the mask layer exposed by the second photoresist layer; and
removing the second photoresist layer.
13. The method recited in claim 11, wherein the fourth pattern is a combination pattern of the first pattern, the second pattern and the third pattern.
14. The method recited in claim 11, wherein a pitch of a combination pattern of the first pattern and the second pattern is smaller than the optical resolution of the multiple patterning process.
15. The method recited in claim 11, wherein the first pattern is different from the second pattern.
16. The method recited in claim 11, wherein the mask layer is made of a bottom anti-reflection coating material.
17. The method recited in claim 16, wherein the bottom anti-reflection coating material is dissolved in a developer used for patterning the first photoresist layer and the second photoresist layer and is not dissolved in a stripping solvent for removing the first photoresist layer and the second photoresist layer.