Vertical transistor with dielectrically-isolated work-function metal electrodes surrounding the semiconductor pillar

Patent metadata

Field	Value
Publication number	US-9024376-B2
Application number	US-201414160788-A
Country	US
Kind code	B2
Filing date	Jan 22, 2014
Priority date	Jan 25, 2013
Publication date	May 5, 2015
Grant date	May 5, 2015

Abstract

A semiconductor device includes a pillar-shaped semiconductor having an impurity concentration of 10 17 cm −3 or less, a first insulator that surrounds the pillar-shaped semiconductor, a first metal that surrounds a portion of the first insulator at a first end of the pillar-shaped semiconductor, a second metal that surrounds a portion of the first insulator at the second end of the pillar-shaped semiconductor, a third metal that surrounds a portion of the first insulator in a region sandwiched between the first metal and the second metal, a second insulator formed between the first and third metals, a third insulator formed between the second and third metals, a fourth metal that connects the first metal and the one end, and a fifth metal that connects the second metal and the other end. The third metal has a work function of about 4.2 eV to about 5.0 eV.

First claim

The invention claimed is:

1. A semiconductor device comprising:
a pillar-shaped semiconductor having an impurity concentration of 10 17 cm −3 or less;
a first insulator surrounding the pillar-shaped semiconductor;
a first metal surrounding a portion of the first insulator at a first end of the pillar-shaped semiconductor;
a second metal surrounding a portion of the first insulator at a second end of the pillar-shaped semiconductor;
a third metal surrounding a portion of the first insulator in a region sandwiched between the first metal and the second metal;
a second insulator between the first metal and the third metal;
a third insulator between the second metal and the third metal;
a fourth metal connecting the first metal and the first end of the pillar-shaped semiconductor; and
a fifth metal connecting the second metal and the second end of the pillar-shaped semiconductor,
wherein the third metal has a work function of about 4.2 eV to about 5.0 eV.

2. The semiconductor device according to claim 1 , wherein the semiconductor comprises silicon.

3. The semiconductor device according to claim 2 , wherein the first metal and the second metal have a work function of about 4.0 eV to about 4.2 eV.

4. The semiconductor device according to claim 2 , wherein the first metal and the second metal have a work function of about 5.0 eV to about 5.2 eV.

5. A semiconductor device comprising:
a pillar-shaped semiconductor;
a first insulator surrounding the pillar-shaped semiconductor;
a first metal surrounding a portion of the first insulator at a first end of the pillar-shaped semiconductor;
a second metal surrounding a portion of the first insulator at a second end of the pillar-shaped semiconductor;
a third metal surrounding a portion of the first insulator in a region sandwiched between the first metal and the second metal;
a second insulator between the first metal and the third metal;
a third insulator between the second metal and the third metal;
a fourth metal connecting the first metal and the first end of the pillar-shaped semiconductor; and
a fifth metal connecting the second metal and a second end of the pillar-shaped semiconductor.

6. The semiconductor device according to claim 5 , wherein charge carriers are induced at the first end of the pillar-shaped semiconductor by a difference in a work function between the pillar-shaped semiconductor and the first metal, and carriers are induced at the second end of the pillar-shaped semiconductor by a difference in the work function between the pillar-shaped semiconductor and the second metal.

7. A semiconductor device comprising:
a pillar-shaped semiconductor;
a first insulator surrounding a portion of the pillar-shaped semiconductor at end of the pillar-shaped semiconductor;
a first metal surrounding the first insulator;
a fourth insulator surrounding a portion of the pillar-shaped semiconductor at the end of the pillar-shaped semiconductor;
a second metal surrounding the fourth insulator;
a fifth insulator surrounding a portion of the pillar-shaped semiconductor in a region sandwiched between the first metal and the second metal;
a third metal surrounding the fifth insulator;
a second insulator between the first metal and the third metal;
a third insulator between the second metal and the third metal;
a fourth metal connecting the first metal and the one end of the pillar-shaped semiconductor; and
a fifth metal connecting the second metal and the other end of the pillar-shaped semiconductor.

8. The semiconductor device according to claim 7 , wherein charge carriers are induced at the first end of the pillar-shaped semiconductor by a difference in a work function between the pillar-shaped semiconductor and the first metal, and charge carriers are induced at the second end of the pillar-shaped semiconductor by a difference in a work function between the pillar-shaped semiconductor and the second metal.

9. A semiconductor device comprising:
a pillar-shaped semiconductor;
a first insulator surrounding at least a part of a portion of the pillar-shaped semiconductor at one end of the pillar-shaped semiconductor;
a first metal surrounding at least a part of the first insulator;
a fourth insulator surrounding at least a part of a portion of the pillar-shaped semiconductor at the end of the pillar-shaped semiconductor;
a second metal surrounding at least a part of the fourth insulator;
a fifth insulator surrounding at least a part of a portion of the pillar-shaped semiconductor in a region sandwiched between the first metal and the second metal;
a third metal surrounding at least a part of the fifth insulator;
a second insulator between the first metal and the third metal;
a third insulator between the second metal and the third metal;
a fourth metal connecting the first metal and the first end of the pillar-shaped semiconductor; and
a fifth metal connecting the second metal and the second end of the pillar-shaped semiconductor.

10. The semiconductor device according to claim 9 , wherein charge carriers are induced at the first end of the pillar-shaped semiconductor by a difference in a work function between the pillar-shaped semiconductor and the first metal, and charge carriers are induced at the second end of the pillar-shaped semiconductor by a difference in a work function between the pillar-shaped semiconductor and the second metal.

Assignees

• Unisantis Elect Singapore Pte

Inventors

• Masuoka Fujio
• Nakamura Hiroki

Classifications

• H10D64/517

  characterised by the conducting layers · CPC title

• H10D64/514

  characterised by the insulating layers · CPC title

• H10D64/258

  characterised by the relative positions of the source or drain electrodes with respect to the gate electrode · CPC title

• H10D62/117

  Shapes of semiconductor bodies · CPC title

• H10D62/83

  being Group IV materials, e.g. B-doped Si or undoped Ge · CPC title