Chemical supply system

Abstract

A chemical supply system comprises, as principal elements, a chemical storage tank in which a liquid chemical for cleaning is stored in the state of its formulated concentrate, a chemical supply apparatus connected to the chemical storage tank for positively performing chemical supply, a piping system connected to the chemical supply apparatus to form a supply flow passage that is a passage for ultrapure water which the liquid chemical is to be mixed with, a pair of discharge nozzles disposed at end portions of the piping system so as to oppose surfaces of a wafer set in a cleaning chamber to supply a cleaning liquid onto the surfaces. Thereby, remarkable miniaturization/simplification of a cleaning liquid supply system including chemical tanks is intended, it is made possible easily and rapidly to compound and supply a cleaning liquid at an accurate chemical concentration, and particles or the like being generated and mixing in a cleaning liquid, are suppressed to the extremity.

1 - 16 . (canceled)  
   
   
       17 . A chemical supply pump in which a flow passage for passing a predetermined liquid chemical is formed, a suction valve which is closed by pressure rise of said liquid chemical is provided at a flowing-in port of said flow passage, and a discharge valve which is closed by pressure fall of said liquid chemical is provided at a flowing-out port of said flow passage, characterized in that 
 at least part of a liquid contact surface in said flow passage is made of a compact member with non-permeability and a high anti-corrosion property to said liquid chemical, and part of said compact member is made into a movable wall, and    a shaker connected to said movable wall is provided, and said movable wall is oscillated in a direction substantially perpendicular to its wall surface by drive of said shaker to change the volume of said flow passage periodically.    
   
   
       18 . A chemical supply pump described in  claim 17 , characterized in that said compact member is conductive.  
   
   
       19 . A chemical supply pump described in  claim 18 , characterized in that said conductive compact member is made of amorphous carbon.  
   
   
       20 . A chemical supply pump described in  claim 17 , characterized in that said compact member is made of ceramics or sapphire.  
   
   
       21 . A chemical supply pump described in  claim 17 , characterized by comprising a drive transmission means for transmitting oscillation from said shaker to said movable wall, between said movable wall and said shaker.  
   
   
       22 . A chemical supply pump described in  claim 21 , characterized by comprising an elastic means for elastically biasing said drive transmission means.  
   
   
       23 . A chemical supply pump described in  claim 21 , characterized in that said shaker is a piezoelectric oscillator for oscillating said movable wall by piezoelectric transduction.  
   
   
       24 . A chemical supply pump described in  claim 18 , characterized in that an opposite wall constituting at least part of said liquid contact surface opposite to said movable wall is made of said conductive compact member, and 
 the electrostatic capacity of a capacitor formed by said movable wall and said opposite wall sandwiching, as a dielectric substance, said liquid chemical passing through said flow passage, is measured.    
   
   
       25 . A chemical supply pump described in  claim 17  characterized in that said movable wall has a shape that becomes thicker from the center to the periphery.  
   
   
       26 . A chemical supply pump described in  claim 21 , characterized in that an auxiliary member for uniformly transmitting the pressure from said drive transmission means to said movable wall is provided between said movable wall and said drive transmission means.  
   
   
       27 . A chemical supply pump described in  claim 21 , characterized in that, in said drive transmission means, in anticipation of reaction received from said liquid chemical when a direct oscillation transmission portion to said movable wall is pressed, said oscillation transmission portion and the portion where said reaction is great are formed to be thicker.  
   
   
       28 . A chemical supply pump described in  claim 17 , characterized in that a gas ventilation system including corner portions which are liquid contact portions of said flow passage and said liquid chemical is apt to stay in, and low-corrosion property portions to said liquid chemical, is provided, and a predetermined gas is passed through said gas ventilation system.  
   
   
       29 . A chemical supply pump described in  claim 28 , characterized in that said corner portions and said low-corrosion property portions include at least the periphery of each of said suction valve, said discharge valve, and said movable wall.  
   
   
       30 . A chemical supply pump described in  claim 17 , characterized in that a cooling means for cooling the interior of said flow passage relatively to the chemical temperature, is provided.  
   
   
       31 . A chemical supply pump described in  claim 17 , characterized in that said shaker controls such that the absolute value of a negative pressure at the time of sucking said liquid chemical in one period of oscillation is as small as possible and the suction time is longer than the discharge time when it oscillates and drives said movable wall.  
   
   
       32 - 62 . (canceled)