Substrate cleaning apparatus and substrate cleaning method

Abstract

A plurality of substrate holding pins 13 extend upright from a holding stage 12, and a substrate W is mechanically held in a circumferential direction with a back surface Sb of the substrate W faced up. Between the substrate W and the holding stage 12, a drip-proof plate 14 whose shape is approximately the same as that of the substrate W is disposed with a distance from the substrate W in such a manner that the drip-proof plate 14 covers a front surface (pattern-bearing surface) Sf of the substrate W from below. The drip-proof plate 14 disposed so as to cover the front surface Sf of the substrate W blocks the mist from splashing upon the front surface Sf of the substrate.

What is claimed is:  
     
         1 . A substrate cleaning apparatus for cleaning one major surface of a substrate, comprising: 
 substrate holding means which holds a substrate with one major surface of said substrate faced up;    cleaning liquid supplying means which includes a cleaning nozzle and which supplies a cleaning liquid at a discharge outlet of said cleaning nozzle onto one major surface of said substrate which is held by said substrate holding means;    ultrasonic wave applying means which is disposed on one major surface side of said substrate and applies ultrasonic vibrations upon said cleaning liquid; and    drip-proof means which is disposed with a distance from said substrate so as to cover other major surface of said substrate from below.    
     
     
         2 . The substrate cleaning apparatus of  claim 1 , further comprising a brush which is disposed adjacent to said discharge outlet of said cleaning nozzle and which is capable of rubbing one major surface of said substrate.  
     
     
         3 . The substrate cleaning apparatus of  claim 2 , further comprising moving means which moves said cleaning nozzle relative to one major surface of said substrate.  
     
     
         4 . The substrate cleaning apparatus of  claim 1 , further comprising rotating means which rotates said substrate and said drip-proof means as one integrated unit.  
     
     
         5 . The substrate cleaning apparatus of  claim 1 , further comprising gas flow generating means which supplies gas into a region-in-space which is located between said other major surface of said substrate and said drip-proof means, to thereby generate a gas flow which travels outward from said region-in-space.  
     
     
         6 . The substrate cleaning apparatus of  claim 5 , wherein said gas flow generating means supplies gas into said region-in-space from an approximately center portion of said drip-proof means.  
     
     
         7 . The substrate cleaning apparatus of  claim 1 , wherein said other major surface of said substrate is a front surface of said substrate which bears a predetermined pattern and one major surface of said substrate is a back surface of said substrate which is to be cleaned.  
     
     
         8 . The substrate cleaning apparatus of  claim 7 , wherein said ultrasonic wave applying means comprises: a transducer which is disposed in the vicinity of one major surface of said substrate; and a high-frequency oscillator which applies an alternating current signal whose frequency is lower than 1.2 MHz upon said transducer.  
     
     
         9 . The substrate cleaning apparatus of  claim 8 , wherein said high-frequency oscillator applies an alternating current signal whose frequency is 400 KHz or lower upon said transducer.  
     
     
         10 . A substrate cleaning method of cleaning a back surface of a substrate whose front surface bears a pattern, comprising the steps of: 
 disposing a substrate in a condition that said back surface of said substrate is faced up and that a gas layer is adjacent to a front surface of said substrate; and    supplying a cleaning liquid upon said back surface of said substrate while ultrasonic vibrations are applied upon said cleaning liquid, to thereby clean said back surface of said substrate with an ultrasonic wave.