Thermoelectric Devices and Methods for Forming Thermoelectric Devices

Abstract

A thermoelectric device includes a plurality of first semiconductor mesa structures having a first conductivity type and a plurality of second semiconductor mesa structures having a second conductivity type. First semiconductor mesa structures of the plurality of first semiconductor mesa structures and second semiconductor mesa structures of the plurality of second semiconductor mesa structures are electrically connected in series. The thermoelectric device further includes a glass structure made of at least one of a borosilicate glass, boron-zinc-glass and a low transition temperature glass. The glass structure is arranged laterally between the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures. The glass structure electrically insulates the first semiconductor mesa structures of the plurality of first semiconductor mesa structures laterally from the second semiconductor mesa structures of the plurality of second semiconductor mesa structures.

What is claimed is: 
     
         1 . A thermoelectric device, comprising:
 a plurality of first semiconductor mesa structures having a first conductivity type;   a plurality of second semiconductor mesa structures having a second conductivity type, first semiconductor mesa structures of the plurality of first semiconductor mesa structures and second semiconductor mesa structures of the plurality of second semiconductor mesa structures being electrically connected in series; and   a glass structure comprising at least one of a borosilicate glass, boron-zinc-glass and a low transition temperature glass, the glass structure being arranged laterally between the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures, the glass structure electrically insulating the first semiconductor mesa structures of the plurality of first semiconductor mesa structures laterally from the second semiconductor mesa structures of the plurality of second semiconductor mesa structures.   
     
     
         2 . The thermoelectric device of  claim 1 , further comprising a plurality of metallization structures located at a side of the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures, wherein each metallization structure of the plurality of metallization structures electrically connects a first semiconductor mesa structure of the plurality of first semiconductor mesa structures to a second semiconductor mesa structure of the plurality of second semiconductor mesa structures. 
     
     
         3 . The thermoelectric device of  claim 1 , wherein a thermal expansion coefficient of the glass structure is greater than 50% and less than 200% of a thermal expansion coefficient of the first semiconductor mesa structures of the plurality of first semiconductor mesa structures. 
     
     
         4 . The thermoelectric device of  claim 1 , wherein the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures comprise at least one of silicon, germanium, silicon-germanium, and bismuth telluride. 
     
     
         5 . The thermoelectric device of  claim 1 , wherein the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures have a maximal lateral dimension of more than 25 μm and less than 250 μm. 
     
     
         6 . The thermoelectric device of  claim 1 , wherein the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures have a vertical dimension of more than 200 μm and less than 1 mm. 
     
     
         7 . The thermoelectric device of  claim 1 , wherein a minimal lateral distance between a first semiconductor mesa structure of the plurality of first semiconductor mesa structures and a second semiconductor mesa structure of the plurality of second semiconductor mesa structures is less than 75% of a maximal lateral dimension of the first semiconductor mesa structures of the plurality of first semiconductor mesa structures. 
     
     
         8 . A thermoelectric device, comprising:
 a plurality of first semiconductor mesa structures having a first conductivity type; and   a plurality of second semiconductor mesa structures having a second conductivity type, wherein second semiconductor mesa structures of the plurality of second semiconductor mesa structures and first semiconductor mesa structures of the plurality of first semiconductor mesa structures are arranged alternating in at least a first lateral direction,   wherein a first lateral distance between two first semiconductor mesa structures of the plurality of first semiconductor mesa structures located closest in the first lateral direction differs from a second lateral distance between two first semiconductor mesa structures of the plurality of first semiconductor mesa structures located closest in a second lateral direction by more than 10% of the first lateral distance.   
     
     
         9 . The thermoelectric device of  claim 8 , further comprising an insulating structure located laterally between the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures, wherein the insulating structure electrically insulates the first semiconductor mesa structures of the plurality of first semiconductor mesa structures laterally from the second semiconductor mesa structures of the plurality of second semiconductor mesa structures. 
     
     
         10 . The thermoelectric device of  claim 9 , wherein the insulating structure comprises at least one of glass, glue, plastics, and laminate. 
     
     
         11 . A method for forming a thermoelectric device, the method comprising:
 forming a plurality of first semiconductor mesa structures at a first semiconductor substrate, the first semiconductor substrate having a first conductivity type;   forming a plurality of second semiconductor mesa structures at a second semiconductor substrate, the second semiconductor substrate having a second conductivity type;   arranging a glass substrate between the first semiconductor substrate and the second semiconductor substrate; and   applying at least one of heat and pressure to the glass substrate to deform the glass substrate so that at least a portion of the glass substrate is moved between first semiconductor mesa structures of the plurality of first semiconductor mesa structures and second semiconductor mesa structures of the plurality of second semiconductor mesa structures, to connect the first semiconductor substrate to the second semiconductor substrate.   
     
     
         12 . The method of  claim 11 , wherein applying heat to the glass substrate comprises a temperature of more than 350° C. 
     
     
         13 . The method of  claim 12 , further comprising heating the first semiconductor substrate, the second semiconductor substrate and the glass substrate to a temperature of more than 350° C. and less than 900° C. 
     
     
         14 . The method of  claim 11 , wherein the glass substrate is a glass wafer or a glass foil comprising comprise at least one of a borosilicate glass, boron-zinc-glass and a low transition temperature glass. 
     
     
         15 . The method of  claim 11 , wherein applying at least one of heat and pressure to the glass substrate comprises pressing the first semiconductor substrate against the second semiconductor substrate with the glass substrate in between and with a pressure force of more than 1 kN and less than 20 kN, to connect the first semiconductor substrate to the second semiconductor substrate. 
     
     
         16 . The method of  claim 11 , wherein forming the plurality of first semiconductor mesa structures comprises forming at least one trench in the first semiconductor substrate, wherein the at least one trench in the first semiconductor substrate is formed by at least one of an etching process, a sawing process, a water jet cutting process, and a laser dicing process. 
     
     
         17 . The method of  claim 11 , further comprising removing a portion of the first semiconductor substrate after the first semiconductor substrate is connected to the second semiconductor substrate, so that the first semiconductor mesa structures of the plurality of first semiconductor mesa structures are separated from each other. 
     
     
         18 . The method of  claim 11 , further comprising forming a plurality of metallization structures located at a side of the first semiconductor mesa structures of the plurality of first semiconductor mesa structures and the second semiconductor mesa structures of the plurality of second semiconductor mesa structures, wherein each metallization structure of the plurality of metallization structures electrically connects a first semiconductor mesa structure of the plurality of first semiconductor mesa structures and a second semiconductor mesa structure of the plurality of second semiconductor mesa structures. 
     
     
         19 . A method for forming a thermoelectric device, the method comprising:
 forming a plurality of first trenches extending into a first semiconductor substrate, first trenches of the plurality of first trenches extending along a first lateral direction, the first semiconductor substrate having a first conductivity type;   forming a plurality of second trenches extending into the first semiconductor substrate, second trenches of the plurality of second trenches extending along a second lateral direction to form a plurality of first semiconductor mesa structures at the first semiconductor substrate;   forming a plurality of third trenches extending into a second semiconductor substrate, third trenches of the plurality of third trenches extending along a third lateral direction, the second semiconductor substrate having a second conductivity type;   forming a plurality of fourth trenches extending into the second semiconductor substrate, fourth trenches of the plurality of fourth trenches extending along a fourth lateral direction to form a plurality of second semiconductor mesa structures at the second semiconductor substrate; and   connecting the first semiconductor substrate to the second semiconductor substrate.   
     
     
         20 . The method of  claim 19 , wherein a width of the second trenches of the plurality of second trenches is less than 90% of a width of the first trenches of the plurality of first trenches.