Chemical etching process and system

Abstract

A chemical etching process and apparatus includes a control unit, an etching unit, an etchant supply unit and an air supply unit. The control unit has a programmable electronic device through which various process parameters are input to control the operations of the etching unit, the etchant supply unit and the air supply unit. The etching unit has an etching table incorporated with the etchant supply unit and the air supply unit for providing a proper etching environment for a working object to be etched. The etchant supply unit is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on/off operation of etchant supply through the control unit. Also, the air supply unit is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on/off operation of air supply through the control unit.

1 . A chemical etching process comprising the steps of: 
 (a) installing a working object to be etched onto an etching table of an etching unit;    (b) spraying an adequate quantity of etchant and stopping the etchant spray after a preset time through a control unit controlling flow control valves and electromagnetic valves of an etchant supply unit;    (c) starting to inject an adequate quantity of air through the control unit controlling flow control valves and electromagnetic valves of an air supply unit in a proper time after the start of spraying etchant in step (b), which is used for removing residues residing in the trenches or on the surface of the working object; and    (d) stopping the air injection after a proper time through the control unit controlling flow control valves and electromagnetic valves of the air supply unit.    
   
   
       2 . The chemical etching process as claimed in  claim 1 , further comprising the steps of: 
 applying a driving gear of the etching unit to tightly fix and then move the working object through the control of the control unit.    
   
   
       3 . The chemical etching process as claimed in  claim 1  or  2 , further comprising the steps of: 
 judging through the control unit if the repeated etching times of step (b) through step (d) attain the required preset etching times; if not, then returning to step (b) and continuing to perform step (b) through step (d); and if yes, then proceeding to next step for further process.    
   
   
       4 . The chemical etching process as claimed in  claim 1  or  2 , further comprising the steps of: 
 determining through the control unit if the etchant needs to be replenished after completion of step (b) through step (d); if yes, then replenishing the etchant and returning to step (b) and continuing to perform the repeated steps; and if not, proceeding to next step for further process.    
   
   
       5 . The chemical etching process as claimed in  claim 1  or  2 , further comprising the steps of: 
 judging through the control unit if the repeated etching time in total of step (b) through step (d) attains the required preset etching time; if not, returning to step (b) and continuing to perform the repeated steps; and if yes, then determining if the etchant needs to be replenished; if yes, returning to step (b) and continuing to perform the repeated steps, and if not, proceeding to next step for further process.    
   
   
       6 . A chemical etching apparatus comprising at least: 
 a control unit having a programmable electronic device through which various process parameters are input to control the operations of various units;    an etching unit having an etching table and necessary apparatuses for providing an proper etching environment for a working object to be etched;    an etchant supply unit being an apparatus for supplying etchant, which is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on/off operation of etchant supply through the control unit;    an air supply unit being an apparatus for injecting air, which is equipped with flow control valves and electromagnetic valves respectively for controlling the flow rate and the on/off operation of air stream through the control unit;    the etchant supply unit comprising a spray element for spraying etchant, which installation direction shall be incorporated with the etching direction of the working object; and    the air supply unit comprising an air nozzle for injecting air, which installation direction shall be incorporated with the etching direction of the working object.    
   
   
       7 . The chemical etching apparatus as claimed in  claim 6 , wherein the etchant supply unit can separately supply various etchants, buffer solutions and de-ionized water for the use of the etching process.  
   
   
       8 . The chemical etching apparatus as claimed in  claim 6 , wherein the etching table of the etchant supply unit comprises a driving gear for tightly fixing and then moving the working object in translation or rotation, a position control element and a speed control element respectively for controlling the position and speed thereof, which are controlled by the control unit outputting control signals thereto.  
   
   
       9 . The chemical etching apparatus as claimed in  claim 6 ,  7  or  8 , wherein the air supply unit comprises multiple air nozzles arranged in proper positions above the surface of the working object for meeting with the needs of the etching process, and each included angle between each of the air nozzles and the surface of the working object can be respectively adjusted upon actual needs, which can be 0 degrees, namely in horizontal.  
   
   
       10 . The chemical etching apparatus as claimed in  claim 6 , wherein an opening of the air nozzle can be flat.  
   
   
       11 . The chemical etching apparatus as claimed in  claim 6 , wherein the air supplied from the air supply unit can be instead of nitrogen gas (N2).  
   
   
       12 . A method for cleaning residual etchants residing on the surface of an etched working object by specific etchants, and the improvements comprising: 
 a high speed air stream being injected across the surface of the working object so as to generate a relative pressure difference on the surface thereof and thus suck out the residual etchants.    
   
   
       13 . The method as claimed in  claim 12 , wherein the direction of the air injection is parallel to the surface of the working object.  
   
   
       14 . The method as claimed in  claim 12 , wherein an included angle between the air injection and the surface of the working object is between 0-30 degrees.  
   
   
       15 . A method for cleaning residues residing in the trenches of a wafer, and the improvements comprising: 
 a high speed air stream being injected across the surface of the wafer so as to generate a relative pressure difference on the surface thereof and thus suck out the residues.    
   
   
       16 . The method as claimed in  claim 15 , wherein the direction of the air injection is parallel to the surface of the wafer.  
   
   
       17 . The method as claimed in  claim 15 , wherein an included angle between the air injection and the surface of the wafer is between 0-30 degrees.