Method for making porous semiconductor membranes

A method for making a porous semiconductor membrane comprising the steps of:

• exposing a first surface of a semiconductor to a fluid including HF and H.sub.2 O which is capable of removing material from said first surface;
• causing an electrical current to flow between said semiconductor and said fluid;
• and
• processing said semiconductor such that a plurality of pores extends through said semiconductor from said first surface to a second surface thereof, thereby creating a porous semiconductor membrane.

A method for making a porous semiconductor membrane comprising the steps of:

• exposing a first surface of a semiconductor to a fluid, including a wetting agent, which is capable of removing material from said first surface;
• preventing said fluid from contacting a second surface of said semiconductor;
• causing an electrical current to flow between said semiconductor and said fluid;
• and
• processing said semiconductor such that a plurality of pores extend through said semiconductor from said first surface to said second surface, thereby creating a porous semiconductor membrane.

A method for making a porous semiconductor membrane comprising the steps of:

• exposing a first surface of a semiconductor to a fluid which is capable of removing material from said first surface:
• causing an electrical current to flow between said semiconductor and said fluid;
• and
• processing said semiconductor such that a plurality of pores extend through said semiconductor from said first surface to a second surface thereof, thereby creating a porous semiconductor membrane, wherein said processing step includes growing pores into said first surface until at least one elongated pore opens on said second surface and then removing material from said second surface in a direction non-parallel to said at least one elongated pore.

A method for making a porous semiconductor membrane comprising of:

• exposing a first surface of a semiconductor to a fluid which is capable of removing material from said first surface;
• causing an electrical current to flow between said semiconductor and said fluid;
• and
• processing said semiconductor such that a plurality of pores extend through said semiconductor from said first surface to a second surface thereof, thereby creating a porous semiconductor membrane, wherein said processing step includes growing pores into said first surface and then removing material from said second surface to expose at least one pore.