Semiconductor device and method of manufacturing the same
View Patent ↗A semiconductor device includes: a monocrystalline substrate; an inter-layer film formed on the monocrystalline substrate; a contact hole penetrating the inter-layer film and partially exposing an upper surface of the monocrystalline substrate; a sidewall formed on an inner surface of the contact hole; a plurality of first monocrystalline layers which include few defects, fill the contact hole, and cover the inter-layer film; and a plurality of second monocrystalline layers which include many defects and cover the sidewall and an upper surface of the inter-layer film so as to be sandwiched between the first monocrystalline layers and the inter-layer film.
1. A semiconductor device, comprising:
a monocrystalline substrate;
an inter-layer film formed on the monocrystalline substrate;
a contact hole penetrating the inter-layer film and partially exposing an upper surface of the monocrystalline substrate;
a sidewall formed on an inner surface of the contact hole;
a plurality of first monocrystalline layers which fill the contact hole and cover the inter-layer film; and
a plurality of second monocrystalline layers which include more defects than those included in the first monocrystalline layers and cover the sidewall and an upper surface of the inter-layer film so as to be sandwiched between the first monocrystalline layers and the inter-layer film.
2. The semiconductor device according to claim 1 , wherein the inter-layer film comprises an insulating film.
3. The semiconductor device according to claim 1 , wherein the inter-layer film comprises insulating films provided on upper and lower surfaces thereof and a non-insulating film sandwiched between the insulating films.
4. The semiconductor device according to claim 1 , wherein the inner surface of the contact hole is perpendicular to the upper surface of the monocrystalline substrate.
5. The semiconductor device according to claim 1 , wherein the contact hole has a taper shape so as to be narrower toward the monocrystalline substrate.
6. The semiconductor device according to claim 1 , wherein the contact hole has a circular cross-section.
7. The semiconductor device according to claim 1 , wherein the contact hole has a substantially rectangular cross-section.
8. The semiconductor device according to claim 1 , wherein two or more layers each comprising the inter-layer-film, the first monocrystalline layers, and the second monocrystalline layers are deposited on the monocrystalline substrate.
9. The semiconductor device according to claim 1 , wherein at least one of a transistor and a wiring is included in at least one of the inter-layer film and the first monocrystalline layers.
10. The semiconductor device according to claim 1 , wherein a plurality of wirings are included in the inter-layer film, any one of the wirings being connected to a memory.
11. The semiconductor device according to claim 9 , wherein the transistor is a thin-film transistor.
12. A method of manufacturing a semiconductor device, comprising:
preparing a monocrystalline substrate;
forming an inter-layer film on the monocrystalline substrate;
forming a contact hole penetrating the inter-layer film and partially exposing an upper surface of the monocrystalline substrate;
forming a first sidewall covering an inner surface of the contact hole;
forming a second sidewall covering the first sidewall;
forming a first monocrystalline layer on the partially-exposed upper surface of the monocrystalline substrate by epitaxial growth;
removing a portion of the second sidewall in contact with the monocrystalline substrate and the first monocrystalline layer by annealing in a reduced atmosphere; and
forming, by repeating the epitaxial growth and the annealing in this order multiple times, a plurality of first monocrystalline layers filling the contact hole and covering the inter-layer film, and a plurality of second monocrystalline layers including more defects than those included in the first monocrystalline layers and covering the first sidewall and an upper surface of the inter-layer film so as to be sandwiched between the first monocrystalline layers and the inter-layer film, the second sidewall being removed and replaced with the second monocrystalline layers.
13. The method according to claim 12 , further comprising forming two or more films each comprising the inter-layer film, the first monocrystalline layers, and the second monocrystalline layers.
14. The method according to claim 12 , wherein the annealing is performed in a hydrogenous atmosphere.
15. The method according to claim 12 , wherein an impurity is implanted into the first and the second monocrystalline layers by in-situ doping.
16. The method according to claim 12 , wherein the first monocrystalline layer is any one of a monocrystalline silicon layer and a monocrystalline SiGe layer.
17. The method according to claim 12 , further comprising digging the monocrystalline substrate by a range of 0.1 to 20 nm before the inter-layer film is formed thereon.
18. The method according to claim 12 , further comprising performing annealing in a reduced atmosphere before the epitaxial growth is firstly performed.
19. The method according to claim 12 , wherein the inter-layer film comprises an insulating film.
20. The method according to claim 12 , further comprising forming at least one of a transistor and a wiring in at least one of the inter-layer film and the first monocrystalline layers formed on the inter-layer film by the epitaxial growth.