Semiconductor device

• US 6,107,654 A
• Filed: 02/08/1999
• Issued: 08/22/2000
• Est. Priority Date: 02/09/1998
• Status: Expired due to Term

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Yamazaki, Shunpei
• Primary Examiner(s): Chaudhuri, Olik
• Assistant Examiner(s): Wille, Douglas A.
• Application Number:
  US09/248,348
• Time in Patent Office: 561 Days
• Field of Search: 257/194
• US Class Current: 257/194
• CPC Class Codes: H01L 21/26506 in group IV semiconductors
• CPC Class Codes: H01L 29/1054 with a variation of the composition, e.g. channel with strained layer for increasing the mobility
• CPC Class Codes: H01L 29/66477 with an insulated gate, i.e. MISFET
• CPC Class Codes: H01L 29/78684 having a semiconductor body comprising semiconductor materials of Group IV not being silicon, or alloys including an element of the group IV, e.g. Ge, SiN alloys, SiC alloys H01L29/7869 takes precedence
• CPC Class Codes: H01L 29/78696 characterised by the structure of the channel, e.g. multichannel, transverse or longitudinal shape, length or width, doping structure, or the overlap or alignment between the channel and the gate, the source or the drain, or the contacting structure of the channel H01L29/78612 takes precedence; transistors having a drain offset region or a lightly doped drain [LDD] H01L29/78621

Abstract

There is provided a semiconductor device having a novel structure in which high operating performance and high reliability can be achieved at the same time.

In an active region 102 sandwiched by a source region 101 and a drain region 103 constituted by a crystalline semiconductor, a Si_X Ge_1-X (0<X<1) region 105 is formed by doping the same with germanium locally. The expansion of a depletion layer from the drain toward the source is effectively suppressed utilizing the difference in the band structures of the Si_X Ge_1-X region 105 and a Si region 106 doped with no germanium.

Claims

1. A semiconductor device comprising.

a circuit formed by a transistor having a configuration including a source region, a drain region and an active region formed using a crystalline semiconductor,

said active region comprising a Si_x Ge_1-x (0<

X<

1) region formed by adding germanium locally thereto and a Si region added with no germanium,

said Si region suppressing expansion of a depletion layer from said drain region toward said source region,

wherein said Si_x Ge_1-x (0<

X<

1) region and said Si region are arranged in said active region substantially in parallel and alternately with each other and arranged perpendicular to a width direction of said active region.

2. A device according to claim 1, wherein said active region comprises a region having a bandgap of Eg₁ and a region having a bandgap of Eg₂ smaller than Eg₁.

3. A device according to claim 2, wherein said region having the bandgap of Eg₁ is the Si region, said region having the bandgap of Eg₂ is the Si_X Ge_1-X (0<

X<

1) region.

4. A device according to claim 1, wherein said Si_X Ge_1-X (0<

X<

1) region is doped with germanium at a concentration such that X is within the range from 0.05 to 0.95.

5. A device according to claim 1, wherein said Si_x Ge_1-x (0<

X<

1) region is formed between said source region and said drain region.

23. A device according to claim 1, wherein said device is one selected from the group consisting of a portable telephone, a video camera, a mobile computer and a projector.

24. A device according to claim 1, wherein said device is an EL display device.

6. A semiconductor device comprising:

a transistor having a configuration including a source region, a drain region and an active region formed using a crystalline semiconductor,

said active region comprising a Si_x Ge_1-x (0<

X<

1) region formed by adding germanium locally thereto and a Si region added with an element selected from element groups 13 and 15 of a long periodic table;

said Si region suppressing expansion of a depletion layer from said drain region toward said source region and controlling a threshold voltage,

wherein said Si_x Ge_1-x (0<

X<

1) region and said Si region are arranged in said active region substantially in parallel and alternately with each other and arranged perpendicular to a width direction of said active region.

7. A device according to claim 6, wherein said active region comprises a region having a bandgap of Eg₁ and a region having a bandgap of Eg₂ smaller than Eg₁.

8. A device according to claim 7, wherein said region having the bandgap of Eg₁ is the Si region, said region having the bandgap of Eg₂ is the Si_x Ge_1-x (0<

X<

1) region.

9. A device according to claim 6, wherein said Si_X Ge_1-X (0<

X<

1) region is doped with germanium at a concentration such that X is within the range from 0.05 to 0.95.

10. A device according to claim 6, wherein said Si_x Ge_1-x (0<

X<

1) region is formed between said source region and said drain region.

25. A device according to claim 6, wherein said device is one selected from the group consisting of a portable telephone, a video camera, a mobile computer and a projector.

26. A device according to claim 6, wherein said device is an EL display device.

11. A semiconductor device comprising:

a circuit formed by a transistor having a configuration including a source region, a drain region and an active region formed using a crystalline semiconductor, and

a Si_x Ge_1-x (0<

X<

1) region formed by adding germanium thereto and a Si region added with no germanium being arranged in said active region substantially in parallel and alternately with each other,

said Si_x Ge_1-x (0<

X<

1) region being formed between said source region and said drain region,

wherein said Si_x Ge_1-x (0<

X<

1) region and said Si region are arranged in said active region substantially in parallel and arranged perpendicular to a width direction of said active region.

12. A device according to claim 11, wherein said active region comprises a region having a bandgap of Eg₁ and a region having a bandgap of Eg₂ smaller than Eg₁.

13. A device according to claim 12, wherein said region having the bandgap of Eg₁ is the Si region, said region having the bandgap of Eg₂ is the Si_X Ge_1-X (0<

X<

1) region.

14. A device according to claim 11, wherein said Si_X Ge_1-X (0<

X<

1) region is doped with germanium at a concentration such that X is within the range from 0.05 to 0.95.

27. A device according to claim 11, wherein said device is one selected from the group consisting of a portable telephone, a video camera, a mobile computer and a projector.

28. A device according to claim 11, wherein said device is an EL display device.

15. A semiconductor device comprising:

a circuit formed by a transistor having a configuration including a source region, a drain region and an active region formed using a crystalline semiconductor, and

Si_x Ge_1-x (0<

X<

1) regions formed by adding germanium thereto being locally formed at the junction between said active region and said source region at intervals from each other,

wherein said Si_x Ge_1-x (0<

X<

1) regions are arranged in parallel and alternately to Si regions with each other and arranged perpendicular to a width direction of said active region.

16. A device according to claim 15, wherein said active region comprises a region having a bandgap of Eg₁ and a region having a bandgap of Eg₂ smaller than Eg₁.

17. A device according to claim 16, wherein said region having the bandgap of Eg₁ is the Si region, said region having the bandgap of Eg₂ is the Si_X Ge_1-X (0<

X<

1) region.

18. A device according to claim 15, wherein said Si_X Ge_1-X (0<

X<

1) region is doped with germanium at a concentration such that X is within the range from 0.05 to 0.95.

29. A device according to claim 15, wherein said device is one selected from the group consisting of a portable telephone, a video camera, a mobile computer and a projector.

30. A device according to claim 15, wherein said device is an EL display device.

19. A semiconductor device comprising:

a circuit formed by a transistor having a configuration including a source region, a drain region and an active region formed using a crystalline semiconductor, and

Si_x Ge_1-x (0<

X<

1) regions formed by adding germanium thereto being locally formed at the junction between said active region and said drain region at intervals from each other,

wherein said Si_x Ge_1-x (0<

X<

1) regions are arranged in parallel and alternately to Si regions with each other and arranged perpendicular to a width direction of said active region.

20. A device according to claim 19, wherein said active region comprises a region having a bandgap of Eg₁ and a region having a bandgap of Eg₂ smaller than Eg₁.

21. A device according to claim 20, wherein said region having the bandgap of Eg₁ is the Si region, said region having the bandgap of Eg₂ is the Si_X Ge_1-X (0<

X<

1) region.

22. A device according to claim 19, wherein said Si_X Ge_1-X (0<

X<

1) region is doped with germanium at a concentration such that X is within the range from 0.05 to 0.95.

31. A device according to claim 19, wherein said device is one selected from the group consisting of a portable telephone, a video camera, a mobile computer and a projector.

32. A device according to claim 19, wherein said device is an EL display device.