Methods and apparatus for airflow and heat management in electroless plating
AssigneeNovellus Systems, Inc.
InventorsSteven T. Mayer, John B. Alexy, Jingbin Feng
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Abstract
Methods and apparatus for reducing heat load and air exposure when using an electroless plating fluid during a plating process, are presented. An electroless plating apparatus, including an electroless plating vessel and recirculation systems, is presented. The electroless plating vessel minimizes air exposure (and thus evaporative cooling and degradation) of the electroless plating fluid while the recirculation systems minimize heat load of the electroless plating fluid.
Claims42
An electroless plating apparatus for reducing loss of electroless plating components from an electroless plating fluid used during an electroless plating process, the apparatus comprising:
- (a) a heat exchange recirculation loop, said heat exchange recirculation loop comprising a heat exchanger and a fluid pump, and an inlet and an outlet of said heat exchange recirculation loop;
- (b) an electroless plating vessel recirculation loop configured in fluid communication with said heat exchange recirculation loop, said electroless plating vessel recirculation loop comprising an electroless plating vessel and configured such that the electroless plating fluid enters the electroless plating vessel recirculation loop via the outlet of the heat exchange recirculation loop and exits the electroless plating vessel recirculation loop at the inlet to the heat exchange recirculation loop;
- (c) a flow meter configured to measure the flow rate of the electroless plating fluid in the electroless plating vessel recirculation loop;
- and
- (d) a flow controller configured to receive flow data input from the flow meter and adjust the amount of the electroless plating fluid that flows through each of the heat exchange recirculation loop and the electroless plating vessel recirculation loop;
- wherein the flow controller is configured to maintain the volumetric flow velocity within the heat exchange recirculation loop at a greater value than the volumetric flow velocity within the electroless plating vessel recirculation loop during the electroless plating process.
An electroless plating vessel comprising:
- (a) a bubble separation chamber, configured to remove bubbles from an electroless plating fluid during an electroless plating process;
- (b) an airflow control device, configured to control exposure of the electroless plating fluid to air during the electroless plating process;
- and
- (c) a ballast tank, configured to receive the electroless plating fluid from a plating chamber of the electroless plating vessel and return the electroless plating fluid to a recirculation loop of an electroless plating apparatus during the electroless plating process, said electroless plating apparatus comprising the electroless plating vessel.
A method of reducing the total head load of an electroless plating fluid during a plating process, the method comprising:
- (a) circulating the electroless plating fluid through a heat exchange recirculation loop at a first volumetric flow velocity, said heat exchange recirculation loop comprising a heat exchanger and a fluid pump, an inlet and an outlet of said heat exchange recirculation loop configured in fluid communication with an electroless plating vessel recirculation loop;
- and
- (b) circulating the electroless plating fluid through said electroless plating vessel recirculation loop at a second volumetric flow velocity, said electroless plating vessel recirculation loop comprising an electroless plating vessel and configured such that the electroless plating fluid enters the electroless plating vessel recirculation loop via the outlet of the beat exchange recirculation loop and exits the electroless plating vessel recirculation loop via the inlet of the heat exchange recirculation loop;
- wherein the first volumetric flow velocity is greater than the second volumetric flow velocity.
A method of removing metal deposits from surfaces of a wafer plating apparatus, the method comprising:
- (a) removing a plating solution from the wafer plating apparatus;
- (b) providing an inorganic acidic medium to the wafer plating apparatus;
- (c) providing an oxidizing medium to the wafer plating apparatus;
- (d) circulating the inorganic acidic medium and the oxidizing medium through the wafer plating apparatus;
- and
- (e) removing the inorganic acidic medium and the oxidizing medium from the wafer plating apparatus.
Dependencies are inferred from the claim text.