Semiconductor device and manufacturing method therefor

• US 20030224550A1
• Filed: 12/18/2002
• Published: 12/04/2003
• Est. Priority Date: 12/21/2001
• Status: Active Grant

• Current Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Original Assignee: Semiconductor Energy Laboratory Co., Ltd.
• Inventors: Shiga, Aiko, Tanada, Yoshifumi, Yamazaki, Shunpei, Kokubo, Chiho
• Granted Patent: US 6,797,550 B2
• Time in Patent Office: Days
• US Class Current: 438/48
• CPC Class Codes: H01L 21/02381 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/0242 Crystalline insulating materials
• CPC Class Codes: H01L 21/02422 Non-crystalline insulating materials, e.g. glass, polymers
• CPC Class Codes: H01L 21/02488 Insulating materials
• CPC Class Codes: H01L 21/02502 consisting of two layers
• CPC Class Codes: H01L 21/02532 Silicon, silicon germanium, germanium
• CPC Class Codes: H01L 21/02609 Crystal orientation
• CPC Class Codes: H01L 21/0268 Shape of mask
• CPC Class Codes: H01L 21/02683 Continuous wave laser beam
• CPC Class Codes: H01L 21/02686 Pulsed laser beam
• CPC Class Codes: H01L 21/02691 Scanning of a beam
• CPC Class Codes: H01L 27/12 the substrate being other than a semiconductor body, e.g. an insulating body
• CPC Class Codes: H01L 27/1285 using control of the annealing or irradiation parameters, e.g. using different scanning direction or intensity for different transistors
• CPC Class Codes: H01L 29/66757 Lateral single gate single channel transistors with non-inverted structure, i.e. the channel layer is formed before the gate
• CPC Class Codes: H01L 29/78675 with normal-type structure, e.g. with top gate

Abstract

To provide a method of efficiently configuring a circuit requiring high inter-device consistency by using thin-film transistors. A semiconductor layer is formed on a substrate and is patterned into desired shapes to form first semiconductor islands. The first semiconductor islands are uniformly crystallized by laser irradiation within the surface areas thereof. Thereafter, the semiconductor layers are patterned into desired shapes to become active layers of the thin-film transistors layer. Active layers of all of thin-film transistors constituting one unitary circuit are formed of one of the first semiconductor islands in this case. Thus, the TFTs mutually realize high consistency.

Claims

1. A manufacturing method for a semiconductor device comprising:

forming an amorphous semiconductor layer on a substrate;

patterning the amorphous semiconductor layer into a desired shape to form first semiconductor islands and markers;

irradiating laser light converged into an elliptical or a rectangular shape to a region including the first semiconductor islands while performing scanning relatively to the substrate to crystallize the first semiconductor islands;

patterning the crystallized first semiconductor islands into desired shapes, and forming second semiconductor islands; and

forming thin-film transistors using the second semiconductor islands as active layers and configuring a circuit by using the thin-film transistors,

wherein active layers of all of thin-film transistors included in a unitary circuit included in the semiconductor device are formed of any one of the crystallized first semiconductor islands.

2. A method according to claim 1, all the thin-film transistors are disposed so that charge movement directions in channel formation regions thereof are consistently arranged approximately parallel.

3. A method according to claim 1, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

4. A method according to claim 1, wherein the laser light is oscillated from any one of a continuous-wave solid laser, a gas laser, and a metal laser.

5. A method according to claim 1, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave YAG laser, YVO₄ laser, YLF laser, YAlO₃ laser, glass laser, ruby laser, alexandrite laser, and Ti:

sapphire laser.

6. A method according to claim 1, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave excimer laser, Ar laser, Kr laser, and CO₂ laser.

7. A method according to claim 1, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave helium-cadmium laser, copper vapor laser, and gold vapor laser.

8. A manufacturing method for a semiconductor device, comprising:

forming an amorphous semiconductor layer on a substrate;

forming a metal-containing layer on the amorphous semiconductor layer, and obtaining a first crystalline semiconductor layer by heat treatment;

patterning the first crystalline semiconductor layer into a desired shape to form first semiconductor islands and markers;

irradiating laser light converged into an elliptical or a rectangular shape onto a region including the first semiconductor islands while performing scanning relatively to the substrate to obtain the first semiconductor islands constituted of second crystalline semiconductor layers;

patterning the first semiconductor islands constituted of the second crystalline semiconductor layers into desired shapes to form second semiconductor islands; and

forming thin-film transistors using the second semiconductor islands as active layers, and configuring a circuit by using the thin-film transistors,

wherein the second semiconductor islands serving as active layers of all of thin-film transistors included in a unitary circuit included in the semiconductor device are formed of any one of the first semiconductor islands constituted of the second crystalline semiconductor layers.

9. A method according to claim 8, all the thin-film transistors are disposed so that charge movement directions in channel formation regions thereof are consistently arranged approximately parallel.

10. A method according to claim 8, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

11. A method according to claim 8, wherein the laser light is oscillated from any one of a continuous-wave solid laser, a gas laser, and a metal laser.

12. A method according to claim 8, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave YAG laser, YVO₄ laser, YLF laser, YAlO₃ laser, glass laser, ruby laser, alexandrite laser, and Ti:

sapphire laser.

13. A method according to claim 8, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave excimer laser, Ar laser, Kr laser, and CO₂ laser.

14. A method according to claim 8, wherein the laser light is oscillated from one laser selected from the group consisting of a continuous-wave helium-cadmium laser, copper vapor laser, and gold vapor laser.

15. A semiconductor device wherein:

an amorphous semiconductor layer is formed on a substrate;

the amorphous semiconductor layer is patterned into a desired shape to form first semiconductor islands and markers;

laser light converged into an elliptical or a rectangular shape is irradiated to a region including the first semiconductor islands while performing scanning relatively to the substrate to crystallize the first semiconductor islands;

the crystallized first semiconductor islands are patterned into desired shapes and second semiconductor islands are formed;

thin-film transistors using the second semiconductor islands as active layers are formed to configure a circuit by using the thin-film transistors; and

the second semiconductor islands serving as active layers of all of thin-film transistors included in a unitary circuit included in the semiconductor device are formed of any one of the crystallized first semiconductor islands.

16. A device according to claim 15, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

17. A semiconductor device wherein:

an amorphous semiconductor layer is formed on a substrate;

a metal-containing layer is formed on the amorphous semiconductor layer to obtain a first crystalline semiconductor layer by heat treatment;

the first crystalline semiconductor layer is patterned into a desired shape to form first semiconductor islands and markers;

laser light converged into an elliptical or a rectangular shape is irradiated onto a region including the first semiconductor islands while performing scanning relatively to the substrate to obtain the first semiconductor islands constituted of second crystalline semiconductor layers;

the first semiconductor islands constituted of the second crystalline semiconductor layers are patterned into desired shapes to form second semiconductor islands;

thin-film transistors using the second semiconductor islands as active layers are formed to configure a circuit by using the thin-film transistors; and

the second semiconductor islands serving as active layers of all of thin-film transistors included in a unitary circuit included in the semiconductor device are formed of any one of the first semiconductor islands constituted of the second crystalline semiconductor layers.

18. A device according to claim 17, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

19. A semiconductor device which has a circuit configured using a plurality of thin-film transistors, comprising one or a plurality of unitary circuits, wherein the second semiconductor islands serving as active layers of all of thin-film transistors included in the unitary circuit are synchronously formed by patterning one first semiconductor island into a desired shape.

20. A device according to claim 19, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

21. A semiconductor device which has a circuit configured using a plurality of thin-film transistors, comprising one or a plurality of unitary circuits,

wherein the second semiconductor islands serving as active layers of all of thin-film transistors included in the unitary circuit are synchronously formed by patterning one first semiconductor island into a desired shape, and

wherein all the thin-film transistors included in the unitary circuit are disposed so that charge movement directions in channel-forming regions thereof are consistently arranged approximately parallel.

22. A device according to claim 21, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.

23. A semiconductor device which has a circuit configured using a plurality of thin-film transistors, comprising one or a plurality of unitary circuits,

wherein the second semiconductor islands serving as active layers of all of thin-film transistors included in the unitary circuit are synchronously formed by patterning one first semiconductor island into a desired shape, and

wherein all the thin-film transistors included in the unitary circuit are disposed so that charge movement directions in channel formation regions thereof are consistently arranged approximately parallel with a scanning direction of laser light that is irradiated to crystallize the first semiconductor islands.

24. A device according to claim 23, wherein the unitary circuit is any one of a current source, a current mirror circuit, a differential amplifier circuit, and an operational amplifier circuit.