Method of forming of a semiconductor film, method of manufacture of a semiconductor device and a semiconductor device

Abstract

This invention provides a method of forming semiconductor films on dielectrics at temperatures below 400° C. Semiconductor films are required for thin film transistors (TFTs), on-chip sensors, on-chip micro-electromechanical systems (MEMS) and monolithic 3D-integrated circuits. For these applications, it is advantageous to form the semiconductor films below 400° C. because higher temperatures are likely to destroy any underlying devices and/or substrates. This invention successfully achieves low temperature growth of germanium films using diboran. First, diboran gas is supplied into a reaction chamber at a temperature below 400° C. The diboran decomposes itself at the given temperature and decomposed boron is attached to the surface of a dielectric, for e.g., SiO 2 , forming a nucleation site and/or a seed layer. Second, source gases for semiconductor film formation, for e.g., SiH 4 , GeH 4 , etc., are supplied into the chamber, thereby forming a semiconductor film.

1 . A semiconductor device having a semiconductor film comprising germanium on an insulating film, wherein a layer comprising boron or boron-doped Si is inserted between the semiconductor film and the insulating film. 
     
     
         2 . The semiconductor device as recited in  claim 1 , wherein the thickness of the insertion layer is at least 2 nm. 
     
     
         3 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film comprises at least phosphorous, boron or antimony. 
     
     
         4 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is a poly-crystalline germanium of (220) orientation. 
     
     
         5 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is a gate electrode. 
     
     
         6 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is a channel. 
     
     
         7 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is formed on multilevel interconnects and at least one layer of interconnects is formed on the semiconductor device. 
     
     
         8 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is a transfer gate (pass transistor). 
     
     
         9 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is an optical detector. 
     
     
         10 . The semiconductor device as recited in  claim 1 , wherein the semiconductor film is a mechanical part.