JP2014183195A5

JP2014183195A5 -

Info

Publication number: JP2014183195A5
Application number: JP2013056803A
Authority: JP
Filing date: 2013-03-19
Publication date: 2016-03-31
Anticipated expiration: 2033-03-19

Claims

A semiconductor substrate;
A first insulating film formed on the semiconductor substrate and having a first opening;
A first groove formed in the semiconductor substrate immediately below the first opening;
A first semiconductor layer formed on the semiconductor substrate in the first trench, including an element different from an element constituting the main component of the semiconductor substrate, and having a forbidden band width smaller than that of the semiconductor substrate. When,
A first element formed on the first semiconductor layer in the first groove, including an element different from an element constituting the main component of the semiconductor substrate, and having a forbidden band width smaller than that of the semiconductor substrate. A conductive second semiconductor layer;
The first semiconductor layer is formed on the second semiconductor layer in the first opening and includes a part of the same element as the main component of the semiconductor substrate, the band gap being the first semiconductor layer and the first semiconductor layer. A third semiconductor layer on the first conductive side larger than the second semiconductor layer;
A metal layer formed on the third semiconductor layer in the first opening ,
An opening region in the upper part of the first groove is formed so as to surround the first opening part, and a ridge made of the first insulating film is formed in the upper part of the first groove, and the first groove is formed. The side wall of the semiconductor substrate includes a (111) plane of the semiconductor substrate, the bottom of the first groove includes a (100) plane of the semiconductor substrate,
The first semiconductor layer includes a (100) plane of the semiconductor substrate that constitutes the first groove bottom, a (111) plane of the semiconductor substrate that constitutes the first trench sidewall, and the first insulating layer. In contact with the lower surface of the ridge formed of a film and the second semiconductor layer;
The second semiconductor layer is in contact with the first semiconductor layer, a lower surface of a ridge formed of the first insulating film, and the third semiconductor layer,
The interface between the first semiconductor layer and the second semiconductor layer is located below the interface between the first semiconductor layer and the first insulating film,
The interface between the third semiconductor layer and the metal layer is located between the lower surface of the first insulating film and the upper surface of the first insulating film,
The semiconductor device, wherein the second semiconductor layer is spatially separated from the semiconductor substrate.

The horizontal length of the ridge formed of the first insulating film is 1/10 or more and 1 or less than the depth of the first groove. Semiconductor device.

3. The semiconductor device according to claim 1, wherein impurity concentrations in the second semiconductor layer and the third semiconductor layer are substantially constant in a depth direction.

The semiconductor device according to claim 1, wherein the first semiconductor layer has a light receiving function.

5. The semiconductor according to claim 1, wherein the semiconductor substrate exhibits a first conductivity type at an interface of the first groove bottom, and the semiconductor device functions as a diode. apparatus.

The semiconductor substrate includes a semiconductor support substrate, an insulating film formed so as to cover the semiconductor support substrate, and a first optical waveguide located on the insulating film and patterned in a waveguide shape. 6. The semiconductor device according to claim 1, wherein the semiconductor device is characterized in that:

The semiconductor substrate covers the first optical waveguide on the first optical waveguide, and has an insulating film having an opening exposing a part of the surface of the first optical waveguide, and the inside of the opening. The semiconductor device according to claim 6, further comprising: a second optical waveguide including a part of the element constituting the semiconductor support substrate on the first optical waveguide.

The semiconductor device according to claim 1, wherein the third semiconductor layer and the metal layer have an ohmic junction interface.

The semiconductor device according to claim 1, wherein the third semiconductor layer and the metal layer have a Schottky junction interface.

The semiconductor support substrate and the first optical waveguide are made of silicon,
The second optical waveguide and the third semiconductor layer are made of silicon or silicon germanium,
Said second semiconductor layer and the first semiconductor layer is composed of germanium or silicon-germanium,
10. The germanium composition of the first semiconductor layer and the second semiconductor layer are both larger than the germanium composition of the second optical waveguide and the third semiconductor layer. The semiconductor device according to any one of the above.

Forming a first insulating film on the semiconductor substrate;
A step of having a first opening in which the semiconductor substrate is exposed in the first insulating film;
Forming a first groove in the semiconductor substrate immediately below the first opening;
On the semiconductor substrate in the first groove, a first semiconductor layer that includes an element that is different from an element that is a main component of the semiconductor substrate and has a forbidden band width smaller than that of the semiconductor substrate is formed. And a process of
A first conductivity type that includes a part of the first semiconductor layer in the first groove that is different from an element that is a main component of the semiconductor substrate, and has a forbidden band width smaller than that of the semiconductor substrate. Forming a second semiconductor layer of:
On the second semiconductor layer in the first opening , the same element as the element constituting the main component of the semiconductor substrate is included in a part thereof, and the forbidden band width is the first semiconductor layer and the second semiconductor layer. Forming a third semiconductor layer on the first conductive side larger than the semiconductor layer of
Forming a metal layer on the third semiconductor layer in the first opening ,
The step of forming the first groove is performed by etching the semiconductor substrate in a horizontal direction so that an opening region of the upper part of the first groove is wider than the first opening. A ridge of the first insulating film is formed on the top of the groove, the bottom of the first groove has the (100) surface of the semiconductor substrate, and the side wall of the first groove is (111) of the semiconductor substrate. ) Including a step of adjusting the groove forming conditions so as to have a surface,
In the step of forming the first semiconductor layer, the first semiconductor layer includes the (100) plane of the semiconductor substrate constituting the first groove bottom and the semiconductor constituting the first groove sidewall. The interface between the first semiconductor layer and the second semiconductor layer is in contact with the (111) surface of the substrate and the lower surface of the first insulating film, and the interface between the first semiconductor layer and the second semiconductor layer. Adjusting the formation conditions of the first semiconductor layer so as to be located below the interface of the first insulating film,
The step of forming the second semiconductor layer includes the step of forming the second semiconductor layer so that the second semiconductor layer is in contact with the first semiconductor layer and a lower surface of the first insulating film. Including the step of adjusting the forming conditions,
In the step of forming the third semiconductor layer, the interface between the third semiconductor layer and the metal layer is located between the lower surface of the first insulating film and the upper surface of the first insulating film. As described above, the method for manufacturing a semiconductor device includes a step of adjusting a formation condition of the third semiconductor layer.

12. The method of manufacturing a semiconductor device according to claim 11, wherein a length of the ridge in a horizontal direction is not less than 1/10 times and not more than 1 time with respect to a depth of the first groove.

The formation of the second semiconductor layer and the third semiconductor layer is performed by epitaxial growth with addition of impurities, and the impurity concentration in the second semiconductor layer and the third semiconductor layer is changed with respect to the depth direction. 13. The method of manufacturing a semiconductor device according to claim 11, wherein the method is substantially constant.

As the semiconductor substrate, a substrate having a semiconductor supporting substrate, an insulating film covering the semiconductor supporting substrate, and a single crystal semiconductor layer formed on the insulating film is used. 14. The method of manufacturing a semiconductor device according to claim 11, wherein the first optical waveguide is formed by patterning in a shape.

A substrate in which the semiconductor support substrate and the first optical waveguide are made of silicon;
The second optical waveguide and the third semiconductor layer are made of silicon or silicon germanium,
Said second semiconductor layer and the first semiconductor layer is germanium or silicon-germanium,
12. The germanium compositions of the first semiconductor layer and the second semiconductor layer are both larger than the germanium compositions of the second optical waveguide and the third semiconductor layer. The method for manufacturing a semiconductor device according to claim 14.