Patterned substrate, semiconductor device and nanotube structure

A semiconductor device, comprising:

• a patterned substrate, wherein the patterned substrate comprises, in a vertical direction, a base plate and an AlN layer that are sequentially stacked, the patterned substrate comprises, in the vertical direction, a first surface and a second surface that are oppositely arranged, a bottom surface of the base plate is the first surface of the patterned substrate, the second surface of the patterned substrate is a patterned surface, the second surface is provided with a plurality of grooves that are independent of each other in a horizontal direction and are arranged in an array, and at least part of the base plate is left below each of the plurality of grooves;
• and
• an epitaxial structure, disposed on a side of the patterned substrate, wherein the vertical direction is a direction perpendicular to the second surface, and the horizontal direction is a direction parallel to the second surface, and an interface between the base plate and the AlN layer is parallel to the horizontal direction;
• the patterned surface is an annealed surface;
• each of the plurality of grooves comprises, from bottom to top in the vertical direction, a first part and a second part that are connected with each other, a width of the second part is greater than a width of the first part;
• the width of the first part gradually increases from bottom to top in the vertical direction, the width of the second part gradually increases from bottom to top in the vertical direction, and an increasing amplitude of the width of the first part is less than an increasing amplitude of the width of the second part,
• wherein a thickness of a portion of the AlN layer below each of the plurality of grooves is less than a thickness of a portion of the AlN layer outside the plurality of grooves.

A nanotube structure, comprising:

• a patterned substrate, wherein the patterned substrate comprises, in a vertical direction, a base plate and an AlN layer that are sequentially stacked, the patterned substrate comprises, in the vertical direction, a first surface and a second surface that are oppositely arranged, a bottom surface of the base plate is the first surface of the patterned substrate, the second surface of the patterned substrate is a patterned surface, the second surface is provided with a plurality of grooves that are independent of each other in a horizontal direction and are arranged in an array, and at least part of the base plate is left below each of the plurality of grooves;
• and
• a connection layer, disposed on a side of the patterned substrate, wherein the vertical direction is a direction perpendicular to the second surface, and the horizontal direction is a direction parallel to the second surface, and an interface between the base plate and the AlN layer is parallel to the horizontal direction;
• the patterned surface is an annealed surface;
• each of the plurality of grooves comprises, from bottom to top in the vertical direction, a first part and a second part that are connected with each other, a width of the second part is greater than a width of the first part;
• the width of the first part gradually increases from bottom to top in the vertical direction, the width of the second part gradually increases from bottom to top in the vertical direction, and an increasing amplitude of the width of the first part is less than an increasing amplitude of the width of the second part,
• wherein a thickness of a portion of the AlN layer below each of the plurality of grooves is less than a thickness of a portion of the AlN layer outside the plurality of grooves.