Light-detecting device and manufacturing method thereof

Abstract

A light-detecting device, comprising: a semiconductor substrate 101 that is composed of silicon as a base material, and contains carbon at a predetermined concentration; and an epitaxial layer 102 that is formed on the semiconductor substrate 101 and composed of silicon as a base material, the epitaxial layer 102 including a light-detecting unit (mainly 104) a predetermined distance away from the semiconductor substrate 101, wherein the semiconductor substrate 101 is formed using a crystal growth method from melt obtained by melting a material containing silicon and a material containing carbon so that carbon is contained in the semiconductor substrate 101 at the predetermined concentration.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

These and the other objects, advantages and features of the invention will become apparent from the following description thereof taken in conjunction with the accompanying drawings which illustrate a specific embodiment of the invention.

In the drawings:

FIG. 1 shows a schematic construction of an IT-CCD type solid-state image pickup device;

FIG. 2 is a cross section of an IT-CCD type solid-state image pickup device;

FIG. 3 shows electric potential distribution in a semiconductor substrate and an epitaxial layer;

FIG. 4 shows a manufacturing method of a solid-state image pickup device;

FIG. 5 shows a manufacturing method of a solid-state image pickup device;

FIG. 6 shows a manufacturing method of a solid-state image pickup device;

FIG. 7 is a comparative result of the number of white scratches;

FIG. 8 is a comparative result of a blooming suppression voltage;

FIG. 9 is a cross section of a wafer;

FIG. 10 shows electric potential distribution in a solid-state image pickup device;

FIG. 11 shows a schematic construction of a FT-CCD type solid-state image pickup device;

FIG. 12 is a cross section of a FT-CCD type solid-state image pickup device;

FIG. 13 is a cross section of a light-receiving element for photocoupler;

FIG. 14 is a comparative result of a resistivity variation in a same plane in an epitaxial layer; and

FIG. 15 is an observation result of a striation.

Claims

1. A light-detecting device, comprising: a semiconductor substrate that is composed of a first element as a base material, and contains a second element at a predetermined concentration, the second element being a homologous element of the first element; andan epitaxial layer that is formed on the semiconductor substrate and composed of the first element as a base material, the epitaxial layer including a light-detecting unit a predetermined distance away from the semiconductor substrate, whereinthe semiconductor substrate is formed using a crystal growth method from melt obtained by melting a material containing the first element and a material containing the second element so that the second element is contained in the semiconductor substrate at the predetermined concentration.

2. The light-detecting device of claim 1, wherein the first element is silicon, the second element is carbon, andthe predetermined concentration is in a range of 1×1016 atoms/cm3 to 2.5×1017 atoms/cm3 inclusive.

3. The light-detecting device of claim 1, wherein a number of BMDs included in the semiconductor substrate per unit area of a cross section is in a range of 5×105/cm2 to 5×107/cm2 inclusive.

4. The light-detecting device of claim 1, wherein a size of a BMD included in the semiconductor substrate is in a range of 50 nm to 400 nm inclusive.

5. The light-detecting device of claim 1, wherein a thickness of the epitaxial layer is in a range of 4 μm to 6 μm inclusive.

6. The light-detecting device of claim 1, wherein a ratio ρ2/ρ1 is in a range of 20 to 200 inclusive, ρ1 being a resistivity of the semiconductor substrate and ρ2 being a resistivity of the epitaxial layer.

7. A light-detecting device, comprising: a semiconductor substrate that is composed of a first element as a base material, and contains a second element at a predetermined concentration, the second element being a homologous element of the first element; andan epitaxial layer that is formed on the semiconductor substrate and composed of the first element as a base material, the epitaxial layer including a light-detecting unit a predetermined distance away from the semiconductor substrate, whereinthe second element is substantially uniformly distributed in the entire semiconductor substrate.

8. The light-detecting device of claim 7, wherein the first element is silicon, the second element is carbon, andthe predetermined concentration is in a range of 1×1016 atoms/cm3 to 2.5×1017 atoms/cm3 inclusive.

9. The light-detecting device of claim 7, wherein a number of BMDs included in the semiconductor substrate per unit area of a cross section is in a range of 5×105/cm2 to 5×107/cm2 inclusive.

10. The light-detecting device of claim 7, wherein a size of a BMD included in the semiconductor substrate is in a range of 50 nm to 400 nm inclusive.

11. The light-detecting device of claim 7, wherein a thickness of the epitaxial layer is in a range of 4 μm to 6 μm inclusive.

12. The light-detecting device of claim 7, wherein a ratio ρ2/ρ1 is in a range of 20 to 200 inclusive, ρ1 being a resistivity of the semiconductor substrate and ρ2 being a resistivity of the epitaxial layer.

13. A manufacturing method of a light-detecting device, comprising the steps of: preparing a semiconductor substrate that is composed of a first element as a base material, and contains a second element at a predetermined concentration, the second element being a homologous element of the first element;growing an epitaxial layer that is composed of the first element as a base material on the semiconductor substrate; andforming a light-detecting unit in the epitaxial layer a predetermined distance away from the semiconductor substrate, whereinthe semiconductor substrate is formed using a crystal growth method from melt obtained by melting a material containing the first element and a material containing the second element so that the second element is contained in the semiconductor substrate at the predetermined concentration.

14. The manufacturing method of claim 13, wherein the first element is silicon, the second element is carbon, andthe predetermined concentration is in a range of 1×1016 atoms/cm3 to 2.5×1017 atoms/cm3 inclusive.

15. The manufacturing method of claim 13, further comprising a step of: performing a heat treatment repeatedly on the semiconductor substrate after the growing step, whereina first input temperature of the heat treatment is in a range of 600 degrees centigrade to 700 degrees centigrade inclusive.

16. The manufacturing method of claim 13, further comprising a step of: performing a heat treatment on the semiconductor substrate before a gate insulator is formed on the epitaxial layer, whereinthe heat treatment is performed under a condition that a highest temperature is in a range of 1000 degrees centigrade to 1100 degrees centigrade inclusive, and a processing time is in a range of 60 minutes to 600 minutes inclusive.

17. The light-detecting device of claim 13, wherein a thickness of the epitaxial layer is in a range of 4 μm to 6 μm inclusive.

18. The light-detecting device of claim 13, wherein a ratio ρ2/ρ1 is in a range of 20 to 200 inclusive, ρ1 being a resistivity of the semiconductor substrate and ρ2 being a resistivity of the epitaxial layer.