Multiple wafer single bath etcher

Abstract

An etcher comprises a bath, a plurality of blades, and a tunnel. The bath includes a first electrode at a first end and a second electrode at a second end. The plurality of blades is configured to fit in the bath. At least one blade of the plurality of blades holds a wafer. At least one tunnel is configured to fit between adjacent blades of the plurality of blades in the bath.

What is claimed is: 
     
         1 . An etcher, comprising:
 a bath with a first electrode at a first end and a second electrode at a second end;   a plurality of blades configured to fit in the bath, wherein at least one blade of the plurality of blades holds a wafer, wherein the first blade holds the wafer using a vacuum clamp at a backside outer edge of the wafer; and   at least one tunnel, wherein the at least one tunnel is configured to fit between adjacent blades of the plurality of blades in the bath.   
     
     
         2 . An etcher of  claim 1 , further comprising a lid that covers the bath. 
     
     
         3 . An etcher of  claim 1 , wherein the vacuum clamp comprises a vacuum space between two concentric seals and the backside outer edge of the wafer. 
     
     
         4 . An etcher of  claim 1 , wherein the first blade has a seal at an outer edge. 
     
     
         5 . An etcher of  claim 1 , wherein the first blade has one or more robot grasping features. 
     
     
         6 . An etcher of  claim 5 , wherein a grasping feature of the one or more robot grasping feature comprises one or more of the following: a hole, a ledge, a peg, a lip, or a slot. 
     
     
         7 . An etcher of  claim 1 , wherein the tunnel includes one or more top slots. 
     
     
         8 . An etcher of  claim 1 , wherein the tunnel is attached to a holder. 
     
     
         9 . An etcher of  claim 1 , further comprising a sparger. 
     
     
         10 . An etcher of  claim 9 , wherein the sparger includes holes to enable liquid to move near an etch side of the wafer. 
     
     
         11 . An etcher of  claim 10 , wherein the holes are situated circumferentially at a shallow angle to the etch side of the wafer. 
     
     
         12 . An etcher of  claim 9 , wherein the sparger is attached to the tunnel. 
     
     
         13 . An etcher of  claim 1 , further comprising a temperature controller. 
     
     
         14 . An etcher of  claim 1 , wherein the first electrode comprises a wire mesh. 
     
     
         15 . An etcher of  claim 14 , wherein the wire mesh comprises a platinum mesh with a  1  to  10  mm grid spacing. 
     
     
         16 . An etcher of  claim 15 , wherein the minimum wire density is achieved using a wire size of 0.25 to 2 mm diameter with a 1 to 10 mm grid spacing. 
     
     
         17 . A method for etching, comprising:
 providing a bath with a first electrode at a first end and a second electrode at a second end;   providing a plurality of blades configured to fit the bath, wherein a first blade of the plurality of blades holds a wafer, wherein the first blade holds the wafer using a vacuum clamp at a backside outer edge of the wafer;   providing a tunnel, wherein the tunnel is configured to fit between the first blade of the plurality of blades and a second blade of the plurality of blades in the bath; and   etching the wafer.