Method of and apparatus for dispensing photoresist in manufacturing semiconductor devices or the like

Photoresist dispensing apparatus for use in coating a substrate with photoresist, the photoresist dispensing apparatus comprising:

• at least one bottle containing photoresist;
• a spray nozzle;
• a supply line connecting the spray nozzle to the at least one bottle so that photoresist can be supplied from the at least one bottle to the spray nozzle;
• a first filter disposed in the supply line at an end of the supply line proximate the spray nozzle, the first filter being of a type that will remove foreign substances from the photoresist;
• a dispensing pump connected to the supply line upstream of the first filter to deliver photoresist through the first filter and spray nozzle;
• a first charge pump connected to the supply line upstream of the dispensing pump to coerce photoresist into the supply line from the at least one bottle;
• a first buffer tank disposed in the supply line downstream of the first charge pump so as to store a volume of photoresist delivered thereto by the first charge pump;
• a bubble removal filter disposed in the supply line downstream of the first buffer tank and upstream of the first filter, the bubble removal filter being of a type that will remove air bubbles from the photoresist;
• a second charge pump disposed in the supply line downstream of the first buffer tank and positioned to deliver photoresist from the first buffer tank to the bubble removal filter;
• and
• a second buffer tank disposed in the supply line between the bubble removal filter and the dispensing pump so as to store a volume of the photoresist, from which the bubbles have been removed by the bubble removal filter, for delivery to the spray nozzle by the dispensing pump.

An assembly for use in a photoresist dispensing apparatus having at least one bottle for containing photoresist, a spray nozzle, and a supply line for connecting the spray nozzle to the at least one bottle, the assembly comprising:

• a first filter of a type that will remove foreign substances from photoresist;
• a dispensing pump connected in-line with and upstream of the first filter with respect to a flow direction in which photoresist is to flow through the assembly;
• a charge pump connected in-line with and upstream of the dispensing pump with respect to the flow direction;
• a bubble removal filter disposed in-line with and downstream of the charge pump and upstream of the first filter with respect to the flow direction, the bubble removal filter being of a type that will remove air bubbles from photoresist, and
• a buffer tank disposed in-line with and between the bubble removal filter and the dispensing pump with respect to the flow direction so as to store a volume of photoresist from which the bubbles have been removed by the bubble removal filter.

Photoresist dispensing apparatus for use in coating a substrate with photoresist, the photoresist dispensing apparatus comprising:

• at least one bottle containing photoresist;
• a spray nozzle;
• a supply line connecting the spray nozzle to the at least one bottle so that photoresist can be supplied from the at least one bottle to the spray nozzle;
• a filter disposed in the supply line at an end of the supply line proximate the spray nozzle, the first filter being of a type that will remove foreign substances from the photoresist;
• a dispensing pump connected to the supply line upstream of the first filter to deliver photoresist through the first filter and spray nozzle;
• a charge pump connected to the supply line upstream of the dispensing pump to coerce photoresist into the supply line from the at least one bottle, the charge pump having a higher capacity, in terms of pressure generated, than the dispensing pump;
• and
• a buffer tank disposed in the supply line between the charge pump and the dispensing pump so as to store a volume of the photoresist for delivery to the spray nozzle by the dispensing pump.

Photoresist dispensing apparatus for use in coating a substrate with photoresist, the photoresist dispensing apparatus comprising:

• at least one bottle containing photoresist;
• a spray nozzle;
• a supply line connecting the spray nozzle to the at least one bottle so that photoresist can be supplied from the at least one bottle to the spray nozzle;
• a first filter disposed in the supply line at an end of the supply line proximate the spray nozzle, the first filter being of a type that will remove foreign substances from the photoresist;
• a dispensing pump connected to the supply line upstream of the first filter to deliver photoresist through the first filter and spray nozzle;
• and
• a bubble removal filter disposed in the supply line upstream of the first filter and dispensing pump, the bubble removal filter being of a type that will remove air bubbles from the photoresist.

A method of dispensing photoresist onto a wafer, the method comprising:

• operating a dispensing pump to pump the phototoresist at first rate through a spray nozzle oriented to spray the photoresist onto a wafer;
• maintaining a volume of the photoresist in a buffer tank connected to an inlet of the dispensing pump so that a constant supply of the photoresist is provided for the dispensing pump as the dispensing pump is operated;
• and
• operating a charging pump to pump photoresist into the buffer tank at a second rate that is greater than the first rate.