Method for forming semiconductor constructions having a buried bit line

摘要

A method of forming a semiconductor structure, comprises providing a semiconductor substrate (12) having a first doped semiconductor region (14) and a second doped semiconductor region (16) over the first doped semiconductor region. One of the first and second doped semiconductor regions is a p-type region and the other is an n-type region. A trench (19) is formed extending through the second doped semiconductor region and into the first doped semiconductor region. The trench has a sidewall comprising the first and second doped semiconductor regions. A first electrically insulative material (214) is formed within the trench to partially fill the trench, the partially filled trench being filled to above an elevational level of an uppermost portion of the first doped semiconductor region along the sidewall. A metal-containing layer (212) is formed within the partially-filled trench and along the second doped semiconductor region of the sidewall. The method further comprises reacting at least some of the metal from the metal-containing layer with the second doped semiconductor region of the sidewall to form a silicide (26,28,30,32) from the trench sidewall. The silicide is within the second doped semiconductor region and not within the first doped semiconductor region. A second electrically insulative material (18,20) is formed within the trench to cover the silicide.