Method for producing semiconductor device and semiconductor device

Abstract

A method for producing a semiconductor device includes forming a first fin-shaped semiconductor layer and a second fin-shaped semiconductor layer on a substrate using a sidewall formed around a dummy pattern on the substrate. A first insulating film is formed around the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer. A first pillar-shaped semiconductor layer is formed in an upper portion of the first fin-shaped semiconductor layer, and a second pillar-shaped semiconductor layer is formed in an upper portion of the second fin-shaped semiconductor layer.

Claims

1. A method for producing a semiconductor device comprising: a first step comprising: forming a first fin-shaped semiconductor layer and a second fin-shaped semiconductor layer on a substrate using a sidewall formed around a dummy pattern on the substrate as an etching mask to etch the substrate; forming a first insulating film around the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer; etching the first fin-shaped semiconductor layer to reduce a height of the first fin-shaped semiconductor layer and to form a first pillar-shaped semiconductor layer in an upper portion of the first fin-shaped semiconductor layer, and etching the second fin-shaped semiconductor layer to reduce a height of the second fin-shaped semiconductor layer and to form a second pillar-shaped semiconductor layer in an upper portion of the second fin-shaped semiconductor layer.

2. The method for producing a semiconductor device according to claim 1 further comprises: after the first step, a second step comprising: forming first diffusion layers by implanting an impurity into an upper portion of the first pillar-shaped semiconductor layer, an upper portion of the first fin-shaped semiconductor layer and a lower portion of the first pillar-shaped semiconductor layer, and forming second diffusion layers by implanting an impurity into an upper portion of the second pillar-shaped semiconductor layer, an upper portion of the second fin-shaped semiconductor layer and a lower portion of the second pillar-shaped semiconductor layer; after the second step, a third step comprising: forming a gate insulating film, a first polysilicon gate electrode, a second polysilicon gate electrode, and a polysilicon gate line so that the gate insulating film covers side surfaces and upper portions the first pillar-shaped semiconductor layer and the second pillar-shaped semiconductor layer, the first polysilicon gate electrode and the second polysilicon gate electrode covers the gate insulating film, and where after the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line are formed, an upper surface of a polysilicon region is located at a higher position relative to the substrate than the gate insulating film on the diffusion layer in the upper portion of the first pillar-shaped semiconductor layer and the gate insulating film on the diffusion layer in the upper portion of the second pillar-shaped semiconductor layer; after the third step, a fourth step comprising: forming a silicide in an upper portion of the first diffusion layer in the first fin-shaped semiconductor layer and in an upper portion of the second diffusion layer in the second fin-shaped semiconductor layer; after the fourth step, a fifth step comprising: depositing an interlayer insulating film, exposing the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line, etching the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line, then depositing a metal, and forming a first metal gate electrode, a second metal gate electrode, and a metal gate line, the metal gate line being connected to the first metal gate electrode and second metal gate electrode and extending in a direction perpendicular to a direction in which the first fin-shaped semiconductor layer and second fin-shaped semiconductor layer extend; and, after the fifth step, a sixth step comprising: forming a contact that is directly connected to the first diffusion layer in the upper portion of the first pillar-shaped semiconductor layer and the second diffusion layer in the upper portion of the second pillar-shaped semiconductor layer.

3. The method for producing a semiconductor device according to claim 1, wherein the first step further comprises: depositing a second oxide film on the substrate to form the dummy pattern; forming a first resist for forming the dummy pattern; etching the second oxide film to form the dummy pattern; removing the first resist; depositing a first nitride film; forming a first nitride film sidewall around the dummy pattern by etching the first nitride film in such a manner that the first nitride film remains in a sidewall shape; removing the dummy pattern; etching the substrate using the first nitride film sidewall as a mask to form the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer such that they are connected to each other at their ends to form a closed loop; forming the first insulating film around the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer; removing the first nitride film sidewall; etching back the first insulating film to expose an upper portion of the first fin-shaped semiconductor layer and an upper portion of the second fin-shaped semiconductor layer; forming a second resist so as to be perpendicular to the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer; etching the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer; and removing the second resist to form the first pillar-shaped semiconductor layer such that a portion in which the first fin-shaped semiconductor layer is perpendicular to the second resist comprises the first pillar-shaped semiconductor layer and to form the second pillar-shaped semiconductor layer such that a portion in which the second fin-shaped semiconductor layer is perpendicular to the second resist comprises the second pillar-shaped semiconductor layer.

4. The method for producing a semiconductor device according to claim 2, wherein after the first step, the second step further comprises: depositing a third oxide film on the after forming the second pillar-shaped semiconductor layer in the first step; forming a second nitride film; etching the second nitride film such that the second nitride film remains in a sidewall shape; forming the first and second diffusion layers by implanting an impurity into the upper portion of the first pillar-shaped semiconductor layer, the upper portion of the first fin-shaped semiconductor layer, the upper portion of the second pillar-shaped semiconductor layer, and the upper portion of the second fin-shaped semiconductor layer, respectively; removing the second nitride film and the third oxide film; and performing a heat treatment.

5. The method for producing a semiconductor device according to claim 2, wherein after the second step, the third step further comprises: forming the gate insulating film so as to surround the first pillar-shaped semiconductor layer and the second pillar-shaped semiconductor layer; depositing and planarizing a polysilicon such that an upper surface of the planarized polysilicon is located at a higher position, relative to the substrate, than the gate insulating film on the diffusion layer in the upper portion of the first pillar-shaped semiconductor layer and the gate insulating film on the second diffusion layer in the upper portion of the second pillar-shaped semiconductor layer; depositing a third nitride film; forming a third resist for forming the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line; etching the third nitride film and the polysilicon to form the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line; etching the gate insulating film; and removing the third resist.

6. The method for producing a semiconductor device according to claim 2 further comprising: depositing a fourth nitride film after removing the third resist in the third step, etching the fourth nitride film in such that the fourth nitride film remains in a sidewall shape, and depositing a metal to form the silicide in upper portions of the first diffusion layers in the upper portions of the first fin-shaped semiconductor layer and second fin-shaped semiconductor layer.

7. The method for producing a semiconductor device according to claim 6 further comprising: depositing a fifth nitride film on the entire structure after forming the silicide in the fourth step; depositing an interlayer insulating film and planarizing the interlayer insulating film by chemical mechanical polishing, wherein the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line are exposed by the chemical mechanical polishing; etching the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line; depositing a metal to fill portions in which the first polysilicon gate electrode, the second polysilicon gate electrode, and the polysilicon gate line are etched; and etching the metal to expose the gate insulating film on the diffusion layer in the upper portion of the first pillar-shaped semiconductor layer and the gate insulating film on the diffusion layer in the upper portion of the second pillar-shaped semiconductor layer and to form the first metal gate electrode, the second metal gate electrode, and the metal gate line.

8. A method for producing a semiconductor device, the device having: a first fin-shaped semiconductor layer and a second fins-shaped semiconductor layer on a substrate; a first insulating film around the first fin-shaped semiconductor layer and the second fins-shaped semiconductor layer; a first pillar-shaped semiconductor layer on the first fin-shaped semiconductor layer; a second pillar-shaped semiconductor layer on the second fin-shaped semiconductor layer; a first gate insulating film around the first pillar-shaped semiconductor layer; a first metal gate electrode around the first gate insulating film; a second gate insulating film around the second pillar-shaped semiconductor layer; a second metal gate electrode around the second gate insulating film, and a metal gate line connected to the first metal gate electrode and the second metal gate and extending in a direction perpendicular to the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer; the method comprising: forming the first fin-shaped semiconductor layer and the second fin-shaped semiconductor layer using a sidewall formed around a dummy pattern on the substrate as an etching mask to etch the substrate; etching the first and second fin-shaped semiconductor layers to reduce a height of the first and second fin-shaped semiconductor layers and to form the first and second pillar-shaped semiconductor layers, respectively.

Description

BRIEF DESCRIPTION OF THE DRAWING

(1) FIG. 1A is a plan view of a semiconductor device according to an embodiment of the present invention, FIG. 1B is a sectional view taken along line X-X of FIG. 1A, and FIG. 1C is a sectional view taken along line Y-Y of FIG. 1A;

(2) FIG. 2A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 2B is a sectional view taken along line X-X of FIG. 2A, and FIG. 2C is a sectional view taken along line Y-Y of FIG. 2A;

(3) FIG. 3A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 3B is a sectional view taken along line X-X of FIG. 3A, and FIG. 3C is a sectional view taken along line Y-Y of FIG. 3A;

(4) FIG. 4A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 4B is a sectional view taken along line X-X of FIG. 4A, and FIG. 4C is a sectional view taken along line Y-Y of FIG. 4A;

(5) FIG. 5A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 5B is a sectional view taken along line X-X of FIG. 5A, and FIG. 5C is a sectional view taken along line Y-Y of FIG. 5A;

(6) FIG. 6A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 6B is a sectional view taken along line X-X of FIG. 6A, and FIG. 6C is a sectional view taken along line Y-Y of FIG. 6A;

(7) FIG. 7A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 7B is a sectional view taken along line X-X of FIG. 7A, and FIG. 7C is a sectional view taken along line Y-Y of FIG. 7A;

(8) FIG. 8A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 8B is a sectional view taken along line X-X of FIG. 8A, and FIG. 8C is a sectional view taken along line Y-Y of FIG. 8A;

(9) FIG. 9A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 9B is a sectional view taken along line X-X of FIG. 9A, and FIG. 9C is a sectional view taken along line Y-Y of FIG. 9A;

(10) FIG. 10A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 10B is a sectional view taken along line X-X of FIG. 10A, and FIG. 10C is a sectional view taken along line Y-Y of FIG. 10A;

(11) FIG. 11A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 11B is a sectional view taken along line X-X of FIG. 11A, and FIG. 11C is a sectional view taken along line Y-Y of FIG. 11A;

(12) FIG. 12A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 12B is a sectional view taken along line X-X of FIG. 12A, and FIG. 12C is a sectional view taken along line Y-Y of FIG. 12A;

(13) FIG. 13A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 13B is a sectional view taken along line X-X of FIG. 13A, and FIG. 13C is a sectional view taken along line Y-Y of FIG. 13A;

(14) FIG. 14A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 14B is a sectional view taken along line X-X of FIG. 14A, and FIG. 14C is a sectional view taken along line Y-Y of FIG. 14A;

(15) FIG. 15A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 15B is a sectional view taken along line X-X of FIG. 15A, and FIG. 15C is a sectional view taken along line Y-Y of FIG. 15A;

(16) FIG. 16A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 16B is a sectional view taken along line X-X of FIG. 16A, and FIG. 16C is a sectional view taken along line Y-Y of FIG. 16A;

(17) FIG. 17A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 17B is a sectional view taken along line X-X of FIG. 17A, and FIG. 17C is a sectional view taken along line Y-Y of FIG. 17A;

(18) FIG. 18A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 18B is a sectional view taken along line X-X of FIG. 18A, and FIG. 18C is a sectional view taken along line Y-Y of FIG. 18A;

(19) FIG. 19A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 19B is a sectional view taken along line X-X of FIG. 19A, and FIG. 19C is a sectional view taken along line Y-Y of FIG. 19A;

(20) FIG. 20A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 20B is a sectional view taken along line X-X of FIG. 20A, and FIG. 20C is a sectional view taken along line Y-Y of FIG. 20A;

(21) FIG. 21A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 21B is a sectional view taken along line X-X of FIG. 21A, and FIG. 21C is a sectional view taken along line Y-Y of FIG. 21A;

(22) FIG. 22A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 22B is a sectional view taken along line X-X of FIG. 22A, and FIG. 22C is a sectional view taken along line Y-Y of FIG. 22A;

(23) FIG. 23A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 23B is a sectional view taken along line X-X of FIG. 23A, and FIG. 23C is a sectional view taken along line Y-Y of FIG. 23A;

(24) FIG. 24A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 24B is a sectional view taken along line X-X of FIG. 24A, and FIG. 24C is a sectional view taken along line Y-Y of FIG. 24A;

(25) FIG. 25A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 25B is a sectional view taken along line X-X of FIG. 25A, and FIG. 25C is a sectional view taken along line Y-Y of FIG. 25A;

(26) FIG. 26A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 26B is a sectional view taken along line X-X of FIG. 26A, and FIG. 26C is a sectional view taken along line Y-Y of FIG. 26A;

(27) FIG. 27A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 27B is a sectional view taken along line X-X of FIG. 27A, and FIG. 27C is a sectional view taken along line Y-Y of FIG. 27A;

(28) FIG. 28A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 28B is a sectional view taken along line X-X of FIG. 28A, and FIG. 28C is a sectional view taken along line Y-Y of FIG. 28A;

(29) FIG. 29A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 29B is a sectional view taken along line X-X of FIG. 29A, and FIG. 29C is a sectional view taken along line Y-Y of FIG. 29A;

(30) FIG. 30A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 30B is a sectional view taken along line X-X of FIG. 30A, and FIG. 30C is a sectional view taken along line Y-Y of FIG. 30A;

(31) FIG. 31A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 31B is a sectional view taken along line X-X of FIG. 31A, and FIG. 31C is a sectional view taken along line Y-Y of FIG. 31A;

(32) FIG. 32A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 32B is a sectional view taken along line X-X of FIG. 32A, and FIG. 32C is a sectional view taken along line Y-Y of FIG. 32A;

(33) FIG. 33A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 33B is a sectional view taken along line X-X of FIG. 33A, and FIG. 33C is a sectional view taken along line Y-Y of FIG. 33A;

(34) FIG. 34A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 34B is a sectional view taken along line X-X of FIG. 34A, and FIG. 34C is a sectional view taken along line Y-Y of FIG. 34A;

(35) FIG. 35A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 35B is a sectional view taken along line X-X of FIG. 35A, and FIG. 35C is a sectional view taken along line Y-Y of FIG. 35A;

(36) FIG. 36A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 36B is a sectional view taken along line X-X of FIG. 36A, and FIG. 36C is a sectional view taken along line Y-Y of FIG. 36A;

(37) FIG. 37A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 37B is a sectional view taken along line X-X of FIG. 37A, and FIG. 37C is a sectional view taken along line Y-Y of FIG. 37A;

(38) FIG. 38A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 38B is a sectional view taken along line X-X of FIG. 38A, and FIG. 38C is a sectional view taken along line Y-Y of FIG. 38A;

(39) FIG. 39A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 39B is a sectional view taken along line X-X of FIG. 39A, and FIG. 39C is a sectional view taken along line Y-Y of FIG. 39A;

(40) FIG. 40A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 40B is a sectional view taken along line X-X of FIG. 40A, and FIG. 40C is a sectional view taken along line Y-Y of FIG. 40A;

(41) FIG. 41A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 41B is a sectional view taken along line X-X of FIG. 41A, and FIG. 41C is a sectional view taken along line Y-Y of FIG. 41A;

(42) FIG. 42A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 42B is a sectional view taken along line X-X of FIG. 42A, and FIG. 42C is a sectional view taken along line Y-Y of FIG. 42A;

(43) FIG. 43A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 43B is a sectional view taken along line X-X of FIG. 43A, and FIG. 43C is a sectional view taken along line Y-Y of FIG. 43A;

(44) FIG. 44A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 44B is a sectional view taken along line X-X of FIG. 44A, and FIG. 44C is a sectional view taken along line Y-Y of FIG. 44A;

(45) FIG. 45A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 45B is a sectional view taken along line X-X of FIG. 45A, and FIG. 45C is a sectional view taken along line Y-Y of FIG. 45A;

(46) FIG. 46A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 46B is a sectional view taken along line X-X of FIG. 46A, and FIG. 46C is a sectional view taken along line Y-Y of FIG. 46A; and

(47) FIG. 47A is a plan view showing a method for producing a semiconductor device according to an embodiment of the present invention, FIG. 47B is a sectional view taken along line X-X of FIG. 47A, and FIG. 47C is a sectional view taken along line Y-Y of FIG. 47A.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

(48) A production process for forming a SGT structure according to an embodiment of the present invention will now be described with reference to FIGS. 2 to 47.

(49) A production method is described that includes forming a first fin-shaped silicon layer and a second fin-shaped silicon layer on a substrate, forming a first insulating film around the first fin-shaped silicon layer and second fin-shaped silicon layer, forming a first pillar-shaped silicon layer in an upper portion of the first fin-shaped silicon layer, and forming a second pillar-shaped silicon layer in an upper portion of the second fin-shaped silicon layer. As shown in FIG. 2, a second oxide film 102 is deposited on a silicon substrate 101 in order to form a dummy pattern. A nitride film or a laminated film of an oxide film and a polysilicon may be used.

(50) As shown in FIGS. 3A-3C, a first resist 103 for forming the dummy pattern is formed.

(51) As shown in FIGS. 4A-4C, the second oxide film 102 is etched to form the dummy pattern 102.

(52) As shown in FIGS. 5A-5C, the first resist 103 is removed.

(53) As shown in FIGS. 6A-6C, a first nitride film 104 is deposited.

(54) As shown in FIGS. 7A-7C, by etching the first nitride film 104, the first nitride film 104 is made to remain in a sidewall shape. Thus, a first nitride film sidewall 104 is formed around the dummy pattern 102. By etching silicon using the formed first nitride film sidewall 104, a first fin-shaped silicon layer 105 and a second fin-shaped silicon layer 106 that are connected to each other at their ends to form a closed loop will be formed.

(55) As shown in FIGS. 8A-8C, the dummy pattern 102 is removed.

(56) As shown in FIGS. 9A-9C, by etching the silicon substrate 101 using the first nitride film sidewall 104 as a mask, a first fin-shaped silicon layer 105 and a second fin-shaped silicon layer 106 that are connected to each other at their ends to form a loop are formed.

(57) As shown in FIGS. 10A-10C, a first insulating film 107 is formed around the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106.

(58) An oxide film formed using high-density plasma or an oxide film formed by low-pressure chemical vapor deposition may be used as the first insulating film.

(59) As shown in FIGS. 11A-11C, the first nitride film sidewall 104 is removed. In the case where the first nitride film sidewall 104 is removed during the silicon etching or the oxide film deposition, this step is skipped.

(60) As shown in FIGS. 12A-12C, the first insulating film 107 is etched back to expose an upper portion of the first fin-shaped silicon layer 105 and an upper portion of the second fin-shaped silicon layer 106.

(61) As shown in FIGS. 13A-13C, a second resist 108 is formed so as to be perpendicular to the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106. The portions in which the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106 are perpendicular to the resist 108 are portions to be formed into pillar-shaped silicon layers. Since the resist can be formed linearly, there is a low probability of the resist falling over after the patterning. Consequently, the process can be stably performed.

(62) As shown in FIGS. 14A-14C, the first fin-shaped silicon layer 105 and the second fin-shaped silicon layer 106 are etched. The portion in which the first fin-shaped silicon layer 105 is perpendicular to the second resist 108 becomes a first pillar-shaped silicon layer 109. The portion in which the second fin-shaped silicon layer 106 is perpendicular to the second resist 108 becomes a second pillar-shaped silicon layer 110. Therefore, the first pillar-shaped silicon layer 109 has a width equal to the width of the first fin-shaped silicon layer 105. The second pillar-shaped silicon layer 110 has a width equal to the width of the second fin-shaped silicon layer 106.

(63) As a result, a structure is formed in which the first pillar-shaped silicon layer 109 is formed in the upper portion of the first fin-shaped silicon layer 105, the second pillar-shaped silicon layer 110 is formed in the upper portion of the second fin-shaped silicon layer 106, and the first insulating film 107 is formed around the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106.

(64) As shown in FIGS. 15A-15C, the second resist 108 is removed.

(65) Next, there is described a production method that includes, in order to achieve gate last, forming diffusion layers by implanting an impurity into an upper portion of the first pillar-shaped silicon layer 109, an upper portion of the first fin-shaped silicon layer 105, and a lower portion of the first pillar-shaped silicon layer 109 and forming diffusion layers by implanting an impurity into an upper portion of the second pillar-shaped silicon layer 110, an upper portion of the second fin-shaped silicon layer 106, and a lower portion of the second pillar-shaped silicon layer 110.

(66) As shown in FIGS. 16A-16C, a third oxide film 111 is deposited and a second nitride film 112 is formed. Since the upper portions of the pillar-shaped silicon layers will be covered with a gate insulating film and a polysilicon gate electrode later, diffusion layers are formed in the upper portions of the pillar-shaped silicon layers before covered with the gate insulating film and polysilicon gate electrode.

(67) As shown in FIGS. 17A-17C, by etching the second nitride film 112, the second nitride film 112 is made to remain in a sidewall shape.

(68) As shown in FIGS. 18A-18C, an impurity such as arsenic, phosphorus, or boron is implanted to form a diffusion layer 113 in the upper portion of the first pillar-shaped silicon layer 109, diffusion layers 115 and 116 in the upper portions of the first fin-shaped silicon layer 105, a diffusion layer 114 in the upper portion of the second pillar-shaped silicon layer 110, and diffusion layers 115 and 116 in the upper portions of the second fin-shaped silicon layer 106.

(69) As shown in FIGS. 19A-19C, the second nitride film 112 and the third oxide film 111 are removed.

(70) As shown in FIGS. 20A-20C, a heat treatment is performed. The diffusion layers 115 and 116 in the upper portions of the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106 are brought into contact with each other and thus a diffusion layer 117 is formed. In order to achieve gate last, the diffusion layers 113 and 117 are formed by implanting an impurity into the upper portion of the first pillar-shaped silicon layer 109, the upper portion of the first fin-shaped silicon layer 105, and the lower portion of the first pillar-shaped silicon layer 109; and the diffusion layers 114 and 117 are formed by implanting an impurity into the upper portion of the second pillar-shaped silicon layer 110, the upper portion of the second fin-shaped silicon layer 106, and the lower portion of the second pillar-shaped silicon layer 110.

(71) Next, there is described a production method that includes, in order to achieve gate last, forming a first polysilicon gate electrode 119b, a second polysilicon gate electrode 119a, and a polysilicon gate line 119c using a polysilicon. To achieve gate last, an interlayer insulating film is deposited and then polysilicon gate electrodes and a polysilicon gate line are exposed by chemical mechanical polishing. Therefore, the upper portions of the pillar-shaped silicon layers need to be prevented from being exposed by the chemical mechanical polishing.

(72) As shown in FIGS. 21A-21C, a gate insulating film 118 is formed and a polysilicon 119 is deposited and planarized. The upper surface of the planarized polysilicon 119 is located at a higher position than the gate insulating film 118 on the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the gate insulating film 118 on the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110. Thus, when the interlayer insulating film is deposited and then the polysilicon gate electrodes and polysilicon gate line are exposed by chemical mechanical polishing in order to achieve gate last, the upper portions of the pillar-shaped silicon layers can be prevented from being exposed by chemical mechanical polishing.

(73) A third nitride film 120 is deposited. The third nitride film 120 is a film that, when a silicide is formed in the upper portions of the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106, prevents the formation of the silicide in upper portions of a first polysilicon gate electrode 119b, a second polysilicon gate electrode 119a, and a polysilicon gate line 119c.

(74) As shown in FIGS. 22A-22C, a third resist 121 for forming a first polysilicon gate electrode 119b, a second polysilicon gate electrode 119a, and a polysilicon gate line 119c is formed. A portion to be the gate line is desirably perpendicular to the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106 to decrease the parasitic capacitance between the gate line and the substrate.

(75) As shown in FIGS. 23A-23C, the third nitride film 120 is etched and the polysilicon 119 is etched to form a first polysilicon gate electrode 119b, a second polysilicon gate electrode 119a, and a polysilicon gate line 119c.

(76) As shown in FIGS. 24A-24C, the gate insulating film 118 is etched.

(77) As shown in FIGS. 25A-25C, the third resist 121 is removed.

(78) The production method that includes, in order to achieve gate last, forming a first polysilicon gate electrode 119b, a second polysilicon gate electrode 119a, and a polysilicon gate line 119c using a polysilicon has been described. The upper surface of the polysilicon after the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c are formed is located at a higher position than the gate insulating film 118 on the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the gate insulating film 118 on the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110.

(79) Next, there is described a production method that includes forming a silicide in the upper portion of the diffusion layer 117 formed in the upper portion of the first fin-shaped silicon layer 105 and in the upper portion of the diffusion layer 117 formed in the upper portion of the second fin-shaped silicon layer 106.

(80) This production method is characterized in that a silicide is not formed in upper portions of the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c and in upper portions of the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110. If a silicide is formed in the upper portions of the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110, the number of production steps is increased.

(81) As shown in FIGS. 26A-26C, a fourth nitride film 122 is deposited.

(82) As shown in FIGS. 27A-27C, by etching the fourth nitride film 122, the fourth nitride film 122 is made to remain in a sidewall shape.

(83) As shown in FIGS. 28A-28C, a metal such as nickel or cobalt is deposited to form a silicide 123 in upper portions of the diffusion layers 117 formed in the upper portions of the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106. Herein, a silicide is not formed in upper portions of the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c because the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c are covered with the fourth nitride film 122 and the third nitride film 120. A silicide is also not formed in upper portions of the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110 because the diffusion layer 113 and the diffusion layer 114 are covered with the gate insulating film 118, the first polysilicon gate electrode 119b, the second polysilicon gate electrode 119a, and the polysilicon gate line 119c.

(84) The production method that includes forming a silicide in the upper portion of the diffusion layer 117 formed in the upper portion of the first fin-shaped silicon layer 105 and forming a silicide in the upper portion of the diffusion layer 117 formed in the upper portion of the second fin-shaped silicon layer 106 has been described.

(85) Next, there is described a production method of gate last that includes depositing an interlayer insulating film 125, exposing the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c, etching the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c, depositing a metal 126, and forming a first metal gate electrode 126b, a second metal gate electrode 126a, and a metal gate line 126c.

(86) As shown in FIGS. 29A-29C, a fifth nitride film 124 is deposited in order to protect the silicide 123.

(87) As shown in FIGS. 30A-30C, an interlayer insulating film 125 is deposited and planarized by chemical mechanical polishing.

(88) As shown in FIGS. 31A-31C, the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c are exposed by chemical mechanical polishing.

(89) As shown in FIGS. 32A-32C, the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c are etched. This etching is desirably performed by wet etching.

(90) As shown in FIGS. 33A-33C, a metal 126 is deposited and planarized to fill, with the metal 126, the portions in which the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c have been present. Atomic layer deposition is preferably used.

(91) As shown in FIGS. 34A-34C, the metal 126 is etched to expose the gate insulating film 118 on the diffusion layer 113 in the upper portion of the first pillar-shaped silicon layer 109 and the gate insulating film 118 on the diffusion layer 114 in the upper portion of the second pillar-shaped silicon layer 110. As a result, a first metal gate electrode 126b, a second metal gate electrode 126a, and a metal gate line 126c are formed.

(92) The production method of gate last that includes depositing the interlayer insulating film 125, exposing the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c, etching the first polysilicon gate electrode 119b, second polysilicon gate electrode 119a, and polysilicon gate line 119c, depositing the metal 126, and forming the first metal gate electrode 126b, the second metal gate electrode 126a, and the metal gate line 126c has been described.

(93) Next, there is described a production method for forming contacts. Since the silicide is not formed in the upper portions of the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the diffusion layer 114 formed in the upper portion of the second pillar-shaped silicon layer 110, a contact is directly connected to the diffusion layer 113 in the upper portion of the first pillar-shaped silicon layer 109 and another contact is directly connected to the diffusion layer 114 in the upper portion of the second pillar-shaped silicon layer 110.

(94) As shown in FIGS. 35A-35C, an interlayer insulating film 127 is deposited and planarized.

(95) As shown in FIGS. 36A-36C, a fourth resist 128 for making a contact hole above the first pillar-shaped silicon layer 109 and second pillar-shaped silicon layer 110 is formed.

(96) As shown in FIGS. 37A-37C, a contact hole 129 is made by etching the interlayer insulating film 127.

(97) As shown in FIGS. 38A-38C, the fourth resist 128 is removed.

(98) As shown in FIGS. 39A-39C, a fifth resist 130 for making contact holes above the metal gate line 126c and above the first fin-shaped silicon layer 105 and second fin-shaped silicon layer 106 is formed.

(99) As shown in FIGS. 40A-40C, contact holes 131 and 132 are made by etching the interlayer insulating films 127 and 125, respectively.

(100) As shown in FIGS. 41A-41C, the fifth resist 130 is removed.

(101) As shown in FIGS. 42A-42C, the fifth nitride film 124 and the gate insulating film 118 are etched to expose the silicide 123 and the diffusion layers 113 and 114, respectively.

(102) As shown in FIGS. 43, a metal is deposited to form contacts 133, 134, and 135. The production method for forming contacts has been described. Since the silicide is not formed in the upper portions of the diffusion layer 113 formed in the upper portion of the first pillar-shaped silicon layer 109 and the diffusion layer 114 in the upper portion of the second pillar-shaped silicon layer 110, the contact 134 is directly connected to the diffusion layer 113 in the upper portion of the first pillar-shaped silicon layer 109 and the other contact 134 is directly connected to the diffusion layer 114 in the upper portion of the second pillar-shaped silicon layer 110.

(103) Next, there is described a production method for forming metal wire layers.

(104) As shown in FIGS. 44A-44C, a metal 136 is deposited.

(105) As shown in FIGS. 45A-45C, sixth resists 137, 138, and 139 for forming metal wires are formed.

(106) As shown in FIGS. 46A-46C, the metal 136 is etched to form metal wires 140, 141, and 142.

(107) As shown in FIGS. 47A-47C, the sixth resists 137, 138, and 139 are removed.

(108) The production method for forming metal wire layers has been described.

(109) FIG. 1 shows a SGT structure formed by the above-described production method.

(110) The SGT structure includes a first fin-shaped semiconductor layer 105 formed on a substrate 101 and a second fin-shaped semiconductor layer 106 formed on the substrate 101, the first fin-shaped semiconductor layer 105 and the second fin-shaped semiconductor layer 106 being connected to each other at their ends to form a closed loop; a first insulating film 107 formed around the first fin-shaped semiconductor layer 105 and second fin-shaped semiconductor layer 106; a first pillar-shaped semiconductor layer 109 formed in an upper portion of the fin-shaped semiconductor layer 105 and a second pillar-shaped semiconductor layer 110 formed in an upper portion of the second fin-shaped semiconductor layer 106, the first pillar-shaped semiconductor layer 109 having a width equal to the width of the first fin-shaped semiconductor layer 105 and the second pillar-shaped semiconductor layer 110 having a width equal to the width of the second fin-shaped semiconductor layer 106; a diffusion layer 117 formed in an upper portion of the first fin-shaped semiconductor layer 105 and a lower portion of the first pillar-shaped semiconductor layer 109, a diffusion layer 113 formed in an upper portion of the first pillar-shaped semiconductor layer 109, a diffusion layer 117 formed in an upper portion of the second fin-shaped semiconductor layer 106 and a lower portion of the second pillar-shaped semiconductor layer 110, and a diffusion layer 114 formed in an upper portion of the second pillar-shaped semiconductor layer 110; a silicide 123 formed in upper portions of the diffusion layers 117 formed in the upper portion of the first fin-shaped semiconductor layer 105 and in the upper portion of the second fin-shaped semiconductor layer 106; a gate insulating film 118 formed around the first pillar-shaped semiconductor layer 109, a first metal gate electrode 126b formed around the gate insulating film 118, a gate insulating film 118 formed around the second pillar-shaped semiconductor layer 110, a second metal gate electrode 126a formed around the gate insulating film 118, and a metal gate line 126c that is connected to the first metal gate electrode 126b and the second metal gate electrode 126a and that extends in a direction perpendicular to the direction in which the first fin-shaped semiconductor layer 105 and second fin-shaped semiconductor layer 106 extend; and a contact 134 formed on the diffusion layer 113 formed in the upper portion of the first pillar-shaped semiconductor layer 109 so as to be directly connected to the diffusion layer 113 and a contact 134 formed on the diffusion layer 114 formed in the upper portion of the second pillar-shaped semiconductor layer 110 so as to be directly connected to the diffusion layer 114.

(111) Accordingly, there are provided a SGT production method in which the parasitic capacitance between a gate line and a substrate is decreased, a gate last process is employed, and two transistors are produced from a single dummy pattern and a SGT structure formed by the production method.