Multi-cathode ionized physical vapor deposition system
A multi-cathode ionized physical vapor deposition system includes a reactor in which a wafer holder is arranged at a bottom wall, and at least two angled cathodes opposite a wafer are arranged at a top wall, each of the cathodes is supplied with a RF current via a matching circuit, and a pressure control mechanism including gas inlets and a gas outlet. In the system, an inner pressure of the reactor is controlled to be relatively high pressure by the pressure control mechanism. Thus, the system can form better side-wall and bottom coverage in patterned holes or trenches on the wafer surface using the atoms sputtered on each of the angled multi-cathodes.
1 . A multi-cathode ionized physical vapor deposition system comprises:
a reactor in which a wafer holder is arranged at a bottom wall so as to be rotated around its central axis, and at least two angled cathodes opposite a wafer placed on said wafer holder are arranged at a top wall,
each of said cathodes is supplied with a RF current from a RF generator via a matching circuit, and
a pressure control mechanism including gas inlets and a gas outlet,
wherein an inner pressure of said reactor is controlled to be a relatively high pressure by said pressure control mechanism.
2 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , further comprising a central cathode parallel to the wafer at a center of said top wall.
3 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , further comprising DC sources for supplying to said cathodes with a DC voltage respectively.
4 . The multi-cathode ionized physical vapor deposition system as claimed in claim 3 , wherein one or more of said cathodes are supplied with DC current in addition to RF current.
5 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , wherein a wafer loaded on said wafer holder is biased.
6 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , wherein the inner pressure of said reactor is higher than 5 Pa.
7 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , wherein the relatively high pressure is a pressure high enough to ionize sputtered atoms by gas phase collisions before the atoms reach the wafer surface.
8 . The multi-cathode ionized physical vapor deposition system comprises:
a reactor in which a wafer holder is arranged at a bottom wall so as to be rotated around its central axis, and at least two angled cathodes opposite a wafer placed on said wafer holder are arranged at a top wall,
each of said cathodes is supplied with a DC voltage from a DC source,
a pressure control mechanism including gas inlets and a gas outlet, and
a central cathode parallel to the wafer at a center of said top wall,
wherein an inner pressure of said reactor is controlled to be a relatively low pressure by said pressure control mechanism, wherein a relatively low pressure means a pressure such that a mean free path of gas atoms is less than or equal to a distance between the cathode and the wafer.
9 . The multi-cathode ionized physical vapor deposition system as claimed in claim 8 , wherein the inner pressure of said reactor is 0.1 Pa at most.
10 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1
wherein target material of either one of said cathodes is a high-dielectric constant material such as HfO 2 or HfSiON.
11 . The multi-cathode ionized physical vapor deposition system as claimed in claim 8 , wherein target material of either one of said cathodes is a high-dielectric constant material such as HfO 2 or HfSiON.
12 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , wherein target materials of the cathodes are dielectric materials or metals such as HfO 2 , Si 3 N 4 , Al 2 O 3 and Hf, which react together to form another dielectric material on the wafer during co-sputtering, where two or more cathodes are given RF or DC voltage at the same time.
13 . The multi-cathode ionized physical vapor deposition system as claimed in claim 8 , wherein target materials of the cathodes are dielectric materials or metals such as HfO 2 , Si 3 N 4 , Al 2 O 3 and Hf, which react together to form another dielectric material on the wafer during co-sputtering, where two or more cathodes are given RF or DC voltage at the same time.
14 . The multi-cathode ionized physical vapor deposition system as claimed in claim 1 , wherein said each cathode has a magnet arrangement on its outside surface to generate magnetic flux that penetrates a cathode surface and reaches the inside of said reactor.