Pre-heat step (or chamber) implemented in pr dry ash machines to effectively eliminate pr extrusion (bubble) after alloy

Abstract

A method for removing a photoresist layer from a semiconductor substrate following a conventional dry etching step. A first wet chemical treatment strips the photoresist. A second dry ash with oxygen plasma completes the photoresist removal. To assure complete removal of photoresist imbedded on or within the material underlying the photoresist film, the semiconductor substrate is preheat treated to a temperature in the range of 150 to 250 degrees Centigrade to release the photoresist prior to the second dry ash with oxygen plasma operation. In particular, this method eliminates photoresist extrusion defects from occurring during a bond pad alloy operation.

What is claimed is:  
     
         1 . A method for removing from a substrate made of semiconductor material a photoresist layer coated on an underlying layer of material comprising the steps of: 
 stripping the photoresist layer from the substrate by a wet chemical treatment;    preheating the substrate to a temperature elevated to release a photoresist residue imbedded within the underlying layer of material;    dry ashing the substrate with an oxygen plasma whereby the photoresist residue is removed from the substrate.    
     
     
         2 . A method as recited in    claim 1    wherein the underlying layer of material is an insulator.  
     
     
         3 . A method as recited in    claim 1    wherein the underlying layer of material is a conductor.  
     
     
         4 . A method as recited in    claim 1    wherein the temperature for preheating the substrate is in the range of 150 to 250 degrees Centigrade.  
     
     
         5 . A method for removing from a substrate made of semiconductor material a patterned photoresist layer overlying a patterned layer of material formed by an etching process comprising the steps of: 
 stripping the patterned photoresist layer from the substrate by a wet chemical treatment;    preheating the substrate to a temperature elevated to release a photoresist residue imbedded within the etched layer of material;    dry ashing the substrate with an oxygen plasma whereby the photoresist residue together with a residues from the etching process and the wet chemical treatment are removed from the substrate.    
     
     
         6 . A method as recited in    claim 5    wherein the patterned layer of material is a patterned insulator layer.  
     
     
         7 . A method as recited in    claim 5    wherein the patterned insulator layer is the passivation layer.  
     
     
         8 . A method as recited in    claim 5    wherein the patterned layer of material is a patterned conductor layer.  
     
     
         9 . A method as recited in    claim 5    wherein the temperature for preheating the substrate is in the range of 150 to 250 degrees Centigrade.  
     
     
         10 . A method for removing from a substrate made of semiconductor material a patterned photoresist layer overlying a passivation layer deposited over an array of bond pads comprising the steps of: 
 etching the passivation layer to form an array of contact openings to the array of bond pads;    stripping the patterned photoresist layer from the substrate by a wet chemical treatment;    preheating the substrate to a temperature elevated to release a photoresist residue imbedded within the passivation layer;    dry ashing the substrate with an oxygen plasma whereby the photoresist residue together with a residues from the etching process and the wet chemical treatment are removed from the substrate.    
     
     
         11 . A method as recited in    claim 1    wherein the temperature for preheating the substrate is in the range of 150 to 250 degrees Centigrade.  
     
     
         12 . A method of preparation for alloying an array of bond pads on a substrate made of semiconductor material overlaid with a passivation layer underlying a patterned photoresist layer comprising the steps of: 
 etching the passivation layer to form an array of contact openings to the array of bond pads;    stripping the patterned photoresist layer from the substrate by a wet chemical treatment;    preheating the substrate to a temperature in the range of 150 to 250 degrees Centigrade to release a photoresist residue imbedded within the etched passivation layer;    dry ashing the substrate with an oxygen plasma whereby the photoresist residue together with a residues from the etching process and the wet chemical treatment are removed from the substrate.    
     
     
         13 . A preheating dry ash integrated multiple modular chamber vacuum processing system for removing a photoresist from a substrate made of semiconductor material comprising: 
 a plurality of interconnected vacuum chambers;    a means for receiving a substrate containing a photoresist within one of the vacuum chambers;    a means for transferring the substrate between the vacuum chambers;    a means for preheating the substrate within at least one of the vacuum chambers;    a means for oxygen plasma dry ashing the substrate in at least one of the vacuum chambers;    a means for cooling the substrate in at least one of the vacuum chambers.    
     
     
         14 . A system as recited in    claim 13    wherein the means for preheating the substrate and the means for oxygen plasma dry ashing the substrate are located in the same chamber.  
     
     
         15 . A system as recited in    claim 13    wherein the means for preheating the substrate and the means for oxygen plasma dry ashing the substrate are located in the same chamber.  
     
     
         16 . A system as recited in    claim 13    wherein the means for preheating the substrate is a temperature controlled hotplate.  
     
     
         17 . A system as recited in    claim 13    wherein the means for preheating the substrate is a temperature controlled source of infrared radiation.  
     
     
         18 . A system as recited in    claim 13    wherein the means for preheating the substrate is a microwave absorptive platen heated by a temperature controlled source of microwave energy.