Semiconductor device and method of manufacturing semiconductor device
The present invention provides a technology which realizes a reliable semiconductor device including a photosensor device by preventing pent roofs of edges of a P + layer from being generated and a metal wiring installed over the P + layer from coming down while securing the electrical conductivity of the P + layer. The semiconductor device includes a photosensor including a photodiode formed on a substrate. The photodiode includes: a cathode electrode; a laminated structure that is formed on the cathode electrode and in which an N + layer, an I layer, and a P + layer are laminated in this order; an anode electrode formed on the P + layer; a first insulating film formed so as to cover a portion of the anode electrode and edges of the laminated structure; and a metal wiring connected to the anode electrode. The edges of the laminated structure are formed in forward tapered shapes in a cross-sectional view.
1. A method of manufacturing a semiconductor device comprising the steps of:
forming a first organic insulating film on a substrate;
selectively forming a cathode electrode on the first organic insulating film;
forming an N + layer so as to cover an upper portion of the first organic insulating film and the cathode electrode;
forming an I layer so as to cover the N + layer;
forming a P + layer so as to cover the I layer;
executing boron ion implantation on the P + layer after the formation of the P + layer;
selectively forming a resist film on the P + layer; and
executing dry etching on the P + layer, the I layer, and the N + layer using the resist film as a mask.
2. The method of manufacturing a semiconductor device according to claim 1 , wherein, in the step of the boron ion implantation, the boron implantation is executed on the P + layer with an acceleration voltage of about 5 keV.
3. The method of manufacturing a semiconductor device according to claim 2 , wherein the film thickness of the P + layer is about 30 nm.
4. The method of manufacturing a semiconductor device according to claim 3 , wherein, in the step of executing dry etching, edges of a laminated structure composed of the P + layer, the I layer, and the N + layer are formed in forward tapered shapes.
5. The method of manufacturing a semiconductor device according to claim 4 , further comprising the steps of:
forming an anode electrode on the P + layer after the step of executing dry etching;
forming a first insulating film so as to cover a portion of the anode electrode and the edges of the laminated structure;
forming a metal wiring in such a way that the metal wiring is connected to the anode electrode and covers a portion of the first insulating film;
forming a second insulating film so as to cover the first insulating film, a portion of the anode electrode, and the metal wiring.
6. The method of manufacturing a semiconductor device according to claim 5 , further comprising the step of forming a second organic insulating film so as to cover the second insulating film.
7. The method of manufacturing a semiconductor device according to claim 6 ,
wherein the cathode electrode is formed of titanium film, and
the anode electrode is formed of transparent electrically conductive film.
8. The method of manufacturing a semiconductor device according to claim 4 , wherein each of the N + layer, the I layer, and the P + layer is formed of a-Si film.
9. The method of manufacturing a semiconductor device according to claim 8 , wherein is about 50 nm, and
the film thickness of the N + layer
the film thickness of the I layer is about 500 nm.
10. The method of manufacturing a semiconductor device according to claim 1 , further comprising a step of forming a thin film transistor on the substrate before the step of forming the first organic insulating film.