Semiconductor component and method of manufacture
View Patent ↗A semiconductor component having a low resistance conduction path and a method for manufacturing the semiconductor component. When the semiconductor component is a Schottky diode, one or more trenches are formed in an epitaxial layer of a first conductivity type that is formed over a semiconductor substrate of the first conductivity type. The trenches may extend into the semiconductor material. Epitaxial semiconductor material of a second conductivity type is selectively grown along the sidewalls of the trenches. An anode contact is formed in contact with the epitaxial layer and the selectively grown epitaxial material and a cathode contact is formed in contact with the semiconductor substrate.
1. A semiconductor component, comprising:
a first semiconductor material of a first conductivity type having first and second major surfaces, wherein the first semiconductor material comprises a semiconductor substrate of the first conductivity type and a first dopant concentration having an epitaxial layer formed thereon, the epitaxial layer of the first conductivity type and a second dopant concentration, wherein the second dopant concentration is less than the first dopant concentration;
a first trench extending from the first major surface into a first portion of the first semiconductor material, the at least one first trench having a sidewall and a floor, wherein a first portion of the first semiconductor material serves as the sidewall and the floor;
a second trench extending from the first major surface into a second portion of the first semiconductor material, the second trench having a floor and first and second opposing sidewalls, wherein the second sidewall of the first trench is spaced apart from the first sidewall of the second trench by a first lateral distance, and wherein a first figure of merit is a product of the first lateral distance and the second dopant concentration;
a layer of intrinsic semiconductor material adjacent to and in direct contact with the sidewall and the floor of the first trench and in direct contact with the sidewall and the floor of the second trench, wherein the intrinsic semiconductor material is a separate material from the first semiconductor material and the sidewalls and the floors of the first trench and the second trench are not formed by the layer of intrinsic material, and wherein a first portion of the layer of intrinsic semiconductor material balances charge in a first direction and a second portion of the layer of intrinsic semiconductor material balances charge in a second direction;
a semiconductor layer on the layer of intrinsic material, wherein a first portion of the semiconductor layer that is adjacent to the sidewall serves to balance charge in the first direction and the second portion of the semiconductor layer serves to balance charge in a second direction; and
an electrically conductive material in direct contact with the first semiconductor material and the layer of intrinsic semiconductor material;
further including a capacitance modulation structure adjacent to the sidewall and the floor of the at least one trench, wherein the layer of intrinsic semiconductor material is between the capacitance modulation structure and the first semiconductor material;
wherein the capacitance modulation structure comprises an air gap;
further including a third semiconductor material adjacent to the second semiconductor material, wherein the third semiconductor material cooperates with the second semiconductor material to balance the charge with the second semiconductor material and wherein the second semiconductor material is of the first conductivity type and the third semiconductor material is of a second conductivity type; and
wherein a dopant concentration of the second and third semiconductor materials is at least ten times greater than a dopant concentration of the first semiconductor material.
2. The semiconductor component of claim 1 , wherein the capacitance modulation structure comprises one of an undoped semiconductor material or a dielectric material.
3. The semiconductor component of claim 1 , further including a sealing cap over the air gap.
4. The semiconductor component of claim 1 , wherein the layer of intrinsic semiconductor material is a selectively grown epitaxial layer.
5. The semiconductor component of claim 4 , wherein the first portion of the layer of intrinsic semiconductor material cooperates with a portion of the first semiconductor material that is adjacent to the sidewall to balance charge in the first direction and the second portion of the layer of intrinsic semiconductor material cooperates with a portion of the first semiconductor material that is adjacent to the floor to balance charge in the second direction.
6. The semiconductor component of claim 1 , further including a capacitance modulation structure adjacent to the sidewall and the floor of the at least one trench.
7. The semiconductor component of claim 1 , further including a first intrinsic semiconductor material between the first semiconductor material and the second semiconductor material.
8. The semiconductor component of claim 7 , further including a second intrinsic semiconductor material between the second semiconductor material and the third semiconductor material.
9. The semiconductor component of claim 1 , further including:
a doped region of the one of the first or a second conductivity type extending from the first major surface into the first semiconductor material; and
a metallization system in direct contact with the doped region and at least the layer of intrinsic semiconductor material.
10. The semiconductor component of claim 1 , further including a doped region extending from the first major surface into the first semiconductor material.
11. The semiconductor component of claim 1 , further including a semiconductor substrate, wherein the first semiconductor material is disposed on the semiconductor substrate, and wherein the at least one trench extends into the semiconductor substrate.