Semiconductor device having MIS field effect transistors or three-dimensional structure

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type;
• an insulating film including a first portion and a second portion formed on the semiconductor substrate;
• a semiconductor projection of the first conductivity type comprising a first side surface and a second side surface formed between the first portion and the second portion of the insulating film, the semiconductor projection being projected from a surface of the insulating film, a bottom of the semiconductor projection being connected to the semiconductor substrate;
• a gate electrode formed on the first side surface of the semiconductor projection with a gate insulating film interposed therebetween;
• a source region and a drain region of a second conductivity type formed in the first side surface of the semiconductor projection, the source region and the drain region being located on both sides of the gate electrode;
• a first impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the first portion of the insulating film;
• a second impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the second portion of the insulating film;
• and
• a contact plug buried in a hole formed in at least one of the first portion and the second portion of the insulating film, the contact plug being connected with a corresponding one of the first and second impurity regions.

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type;
• an insulating film including a first portion and a second portion formed on the semiconductor substrate;
• a semiconductor projection of the first conductivity type comprising a first side surface and a second side surface and a top surface formed between the first portion and the second portion of the insulating film, the semiconductor projection being projected from a surface of the insulating film, a bottom of the semiconductor projection being connected to the semiconductor substrate;
• a gate insulating film formed on the first side surface of the semiconductor projection;
• a gate electrode formed on the gate insulating film on the first side surface of the semiconductor projection and above the top surface of the semiconductor projection;
• an insulating layer formed between the top surface of the semiconductor projection and the gate electrode, the insulating layer being larger in thickness than the gate insulating film;
• a source region and a drain region of a second conductivity type formed in the first side surface of the semiconductor projection, the source region and the drain region being located on both sides of the gate electrode;
• a first impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the first portion of the insulating film;
• and
• a second impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the second portion of the insulating film.

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type;
• an insulating film including a first portion and a second portion formed on the semiconductor substrate;
• a semiconductor projection of the first conductivity type comprising a first side surface and a second side surface formed between the first portion and the second portion of the insulating film, the semiconductor projection being projected from a surface of the insulating film, a bottom of the semiconductor projection being connected to the semiconductor substrate;
• a first gate electrode formed on the first side surface of the semiconductor projection with a gate insulating film interposed therebetween;
• a second gate electrode formed on the second side surface of the semiconductor projection with a gate insulating film interposed therebetween, the second gate electrode being separated from and opposed to the first gate electrode with the semiconductor projection interposed therebetween;
• source regions and drain regions of a second conductivity type formed in the first side surface and the second side surface of the semiconductor projection, the source regions and the drain regions being located on both sides of the first gate electrode and the second gate electrode;
• a first impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the first portion of the insulating film;
• and
• a second impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the second portion of the insulating film.

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type;
• an insulating film including a first portion and a second portion formed on the semiconductor substrate;
• a semiconductor projection comprising a stack of a first impurity region of the first conductivity type, a second impurity region of a second conductivity type and a third impurity region of the first conductivity type, the first impurity region underlying the second impurity region, the second impurity region underlying the third impurity region, the semiconductor projection being formed between the first portion and the second portion of the insulating film, the semiconductor projection being projected from a surface of the insulating film, a bottom of the semiconductor projection being connected to the semiconductor substrate, the semiconductor projection comprising a first side surface and a second side surface of the third impurity region;
• a gate electrode formed on the first side surface of the third impurity region of the semiconductor projection with a gate insulating film interposed therebetween;
• a source region and a drain region of the second conductivity type formed in the first side surface of the third impurity region of the semiconductor projection, the source region and the drain region being located on both sides of the gate electrode;
• a fourth impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the first portion of the insulating film;
• and
• a fifth impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the second portion of the insulating film.

A semiconductor device comprising:

• a semiconductor substrate of a first conductivity type;
• an insulating film including a first portion and a second portion formed on the semiconductor substrate;
• a semiconductor projection of the first conductivity type comprising side surfaces and a top surface formed between the first portion and the second portion of the insulating film, the semiconductor projection being projected from a surface of the insulating film, a bottom of the semiconductor projection being connected to the semiconductor substrate;
• a gate electrode formed on the side surfaces and the top surface of the semiconductor projection with a gate insulating film interposed therebetween, the gate electrode comprising a top surface parallel to a surface of the semiconductor substrate;
• source regions and drain regions of a second conductivity type formed in the side surfaces of the semiconductor projection, the source regions and the drain regions being located on both sides of the gate electrode;
• a first impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the first portion of the insulating film;
• and
• a second impurity region of the first conductivity type formed in a portion of the semiconductor substrate below the second portion of the insulating film, the top surface of the gate electrode being made flat over the top surface of the semiconductor projection and the first and second portions of the insulating film.

A semiconductor device comprising:

• an insulating film formed on a semiconductor substrate;
• a projecting semiconductor layer formed in a hole of the insulating film and extended on the insulating film, the projecting semiconductor layer being projected from a surface of the insulating film, the projecting semiconductor layer comprising end portions and a center portion including a first side surface and a second side surface, a length of the center portion of the projecting semiconductor layer in a width direction being shorter than that of the end portions of the projecting semiconductor layer in the width direction;
• a gate electrode formed on the first side surface of the center portion of the projecting semiconductor layer with a gate insulating film interposed therebetween;
• and
• a source region and a drain region formed in the end portions of the projecting semiconductor layer, the source region and the drain region being located on both sides of the gate electrode.