Copper electrodeposition on cobalt lined features
AssigneeLam Research Corporation
InventorsJeyavel Velmurugan, Bryan L. Buckalew, Thomas A. Ponnuswamy
Life of this patent
Estimating the term…
Abstract
In one example, an electroplating system comprises a bath reservoir, a holding device, an anode, a direct current power supply, and a controller. The bath reservoir contains an electrolyte solution. The holding device holds a wafer submerged in the electrolyte solution. The wafer comprises features covered by a cobalt layer. The anode is opposite to the wafer and submerged in the electrolyte solution. The direct current power supply generates a direct current between the holding device and the anode. A combination of forward and reverse pulses is applied between the holding device and the anode to electroplate a copper layer on the cobalt layer of the wafer.
Claims10
A method for electroplating a wafer, the method comprising:
- submerging the wafer in a bath reservoir containing an electrolyte solution;
- generating a combination of forward and reverse pulses, the combination of forward and reverse pulses including a high convection forward pulse, followed by a high convection reverse pulse, and followed by a low convection reverse pulse, the high convection forward pulse and the high convection reverse pulse each including a convection of at least 150 rpm, the low convection reverse pulse including a convection of at most 20 rpm;
- and
- depositing a copper layer on a cobalt layer of the wafer by applying the combination of forward and reverse pulses to the wafer and an anode disposed opposite to the wafer in the electrolyte solution.
A method comprising:
- providing a semiconductor wafer having a cobalt layer thereon;
- and
- depositing a copper layer on the cobalt layer using an electroplating process by applying a combination of forward direct current pulse and reverse direct current pulse to the semiconductor wafer submerged in an electrolyte solution, wherein the combination of forward direct current pulse and reverse direct current pulse includes a series of a high convection forward pulse, followed by a high convection reverse pulse, and followed by a low convection reverse pulse, the high convection forward pulse and the high convection reverse pulse each including a convection of at least 150 rpm, the low convection reverse pulse includino a convection of at most 20 rpm, wherein the high convection forward pulse includes a convection of at least 150 rpm, wherein the low convection reverse pulse includes a convection of at most 20 rpm.
A machine-readable medium including instructions which, when read by a machine, cause the machine to control operations in an electroplating method, the electroplating method comprising, at least:
- submerging a wafer in a bath reservoir containing an electrolyte solution;
- generating a combination of forward and reverse pulses, the combination of forward and reverse pulses including a high convection forward pulse, followed by a high convection reverse pulse, and followed by a low convection reverse pulse, the high convection forward pulse and the high convection reverse pulse each including a convection of at least 150 rpm, the low convection reverse pulse including a convection of at most 20 rpm;
- and
- depositing a copper layer on a cobalt layer of the wafer by applying the combination of forward and reverse pulses to the wafer and an anode disposed opposite to the wafer in the electrolyte solution.
Dependencies are inferred from the claim text.