1. A method for forming metal lines of a semiconductor device comprising:
forming plugs by providing via-holes in an interlayer dielectric layer formed on a semiconductor substrate and placing a conductive material in the via-holes;
sequentially forming at least two metal layers on the interlayer dielectric layer, the metal layers having a difference in the size of metal grains;
etching an uppermost first metal layer of the at least two metal layers using a photoresist pattern formed on the first metal layer as an etching mask using a first etching gas; and
etching the partially etched first metal layer using a second etching gas.
2. The method according to claim 1, wherein the metal layers are formed such that the size of the metal grains of the at least two metal layers is gradually reduced at each metal layer such that the uppermost first metal layer has the smallest sized metal grains.
3. The method according to claim 1, wherein the first etching gas comprises a mixture of Cl2 and BCl3.
4. The method according to claim 3, wherein the first etching gas etches the first metal layer to a thickness of less than about 20% of the entire thickness of the first metal layer.
5. The method according to claim 3, wherein the second etching gas is obtained by mixing N2 and CHF3 with the first etching gas.
6. The method according to claim 5, wherein etching the partially etched first metal layer comprises changing the concentration of N2 and CHF3 in the second etching gas.
7. The method according to claim 6, wherein the concentration of N2 and CHF3 in the second etching gas is in a range of approximately 1\u02dc10% of the flow rate of the second etching gas.
8. The method according to claim 1, further comprising:
etching a second metal layer below the first metal layer using the first etching gas when the first metal layer is etched.
9. The method according to claim 8, further comprising:
etching the partially etched second metal layer using the second etching gas.
10. The method according to claim 1, further comprising:
removing a residual photoresist pattern using an O2 plasma treatment; and
forming a second interlayer dielectric layer on the etched first metal layer.
11. The method according to claim 1, wherein the at least two metal layers are formed to have metal grains with different sizes by changing the deposition temperature used to form each layer of the at least two metal layers.
12. The method according to claim 1, wherein the at least two metal layers are formed to have metal grains with different sizes by changing the deposition wattage used to form each layer of the at least two metal layers.
13. The method according to claim 1, wherein the at least two metal layers are formed to have metal grains with different sizes by changing the deposition gas pressure used to form each layer of the at least two metal layers.
14. The method according to claim 1, wherein the at least two metal layers comprise aluminum layers.
15. A method for forming metal lines of a semiconductor device comprising:
forming plugs by providing via-holes in an interlayer dielectric layer formed on a semiconductor substrate and providing a conductive material in the via-holes;
sequentially forming at least two metal layers on the interlayer dielectric layer formed with the plugs, the metal layers being formed such that the size of the metal grains of the at least two metal layers is gradually reduced at each metal layer such that an uppermost first metal layer has the smallest sized metal grains;
etching the uppermost first metal layer and a second metal layer below the first metal layer of the at least two metal layers using a photoresist pattern formed on the first metal layer as an etching mask using a first etching gas; and
etching the partially etched first metal layer and second metal layer using a second etching gas.
16. The method according to claim 15, the at least two metal layers are formed to have metal grains with different sizes by changing the deposition temperature used to form each layer of the at least two metal layers.
17. The method according to claim 15, the at least two metal layers are formed to have metal grains with different sizes by changing the deposition wattage used to form each layer of the at least two metal layers.
18. The method according to claim 15, wherein the metal layer forming step sequentially forms the at least two metal layers are formed to have metal grains with different sizes by changing the deposition gas pressure used to form each layer of the at least two metal layers.
19. The method according to claim 15, wherein the at least two metal layers comprise aluminum layers.
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 mounting an over-wheel carrier to the frame of a passenger conveyance having a wheel with an axle and two axle ends, comprising the steps of:
providing a rigid container having a bottom portion, a top portion, and a first and a second side portion and further having a wheel well formed in the bottom portion, a lid disposed on the top portion, a handle hingeably connected to the lid, first and second wheels disposed on respective first and second side portions, first and second lower connector members, and a quick release upper connector disposed to connect the container to the conveyance frame at a location above the conveyance wheel;
engaging the first and second lower connector members at attachment points on opposing sides of the conveyance wheel;
rotating the container along the circumference of the conveyance wheel; and
securing the container to the conveyance frame at the quick release upper connector.
2. The method of claim 1, wherein the providing step further comprises providing a positioning wheel disposed on the bottom portion and coplanar with the wheel well, and further comprising a step of positioning the first and second lower connector members by using the positioning wheel.
3. The method of claim 2, wherein the positioning step solely uses the positioning wheel as guided by the handle.
4. The method of claim 1, wherein the handle is extensible, and further comprising the steps of:
extending the handle prior to the engaging step; and
retracting and stowing the handle after the securing step.