Polycrystalline silicon emitter having an accurately controlled critical dimension

• US 6,965,132 B1
• Filed: 12/17/2002
• Issued: 11/15/2005
• Est. Priority Date: 11/17/2000
• Status: Expired due to Term

• Current Assignee: Newport Fab, LLC (Tower Semiconductor Limited)
• Original Assignee: Newport Fab, LLC (Tower Semiconductor Limited)
• Inventors: Schuegraf, Klaus F.
• Primary Examiner(s): Wilczewski, Mary
• Assistant Examiner(s): Lewis, Monica
• Application Number:
  US10/321,877
• Time in Patent Office: 1,064 Days
• Field of Search: 257/526, 257/183, 257/197, 257/565, 257/370, 257/378, 257/539
• US Class Current: 257/197
• CPC Class Codes: H01L 29/66242 Heterojunction transistors [HBT] with an active layer made of a group 13/15 material H01L29/66318

Abstract

According to a disclosed embodiment, an etch stop layer is fabricated on top of a base. An amorphous layer is then formed on top of the etch stop layer. An opening is then etched in the amorphous layer and the etch stop layer. The opening is etched with an opening width substantially equal to a critical dimension. The opening with opening width substantially equal to a critical dimension is then filled with a polycrystalline emitter. The resulting polycrystalline emitter has an emitter width substantially equal to the critical dimension. Moreover, a polycrystalline emitter structure can be fabricated, in which the critical dimension, i.e. the emitter width, is precisely controlled. The result is a polycrystalline emitter structure which is substantially as small as the resolution that the photolithography process would allow.

Claims

1. A structure comprising:

an etch stop layer on top of a base;

an amorphous layer on top of said etch stop layer;

an anti-reflective coating layer on top of said amorphous layer, said anti-reflective coating layer and said amorphous layer having an opening, said opening having an opening width substantially equal to a critical dimension;

a polycrystalline emitter inside said opening in said anti-reflective coating layer and said amorphous layer, said polycrystalline emitter being in contact with said anti-reflective coating layer and said amorphous layer in said opening, said polycrystalline emitter in said opening having an emitter width substantially equal to said critical dimension;

wherein said polycrystalline emitter has a substantially uniform width in said opening in said anti-reflective coating layer and said amorphous layer.

2. The structure of claim 1 wherein said base comprises silicon-germanium.

3. The structure of claim 1 wherein said amorphous layer comprises amorphous silicon.

4. The structure of claim 1 wherein said etch stop layer comprises silicon oxide.

5. The structure of claim 1 wherein said polycrystalline emitter comprises polycrystalline silicon.

6. The structure of claim 1 wherein said anti-reflective coating layer comprises silicon oxynitride.