Method for forming semiconductor devices using a glass structure attached to a wide band-gap semiconductor wafer
A method for forming semiconductor devices includes: attaching a glass structure to a wide band-gap semiconductor wafer having a plurality of semiconductor devices; forming at least one pad structure electrically connected to at least one doping region of a semiconductor substrate of the wide band-gap semiconductor wafer, by forming electrically conductive material within at least one opening extending through the glass structure; and reducing a thickness of the wide band-gap semiconductor wafer after attaching the glass structure. Additional methods for forming semiconductor devices are described.
1 . A method for forming semiconductor devices, the method comprising:
providing a wide band-gap semiconductor wafer comprising a plurality of semiconductor devices;
forming at least one trench structure extending into the wide band-gap semiconductor wafer between neighboring semiconductor devices of the plurality of semiconductor devices;
attaching a glass structure to the wide band-gap semiconductor wafer after forming the at least one trench structure;
forming at least one pad structure electrically connected to at least one doping region of a semiconductor substrate of the wide band-gap semiconductor wafer, by forming electrically conductive material within at least one opening extending through the glass structure; and
reducing a thickness of the wide band-gap semiconductor wafer after attaching the glass structure.
2 . The method of claim 1 , wherein the plurality of semiconductor devices each comprise a semiconductor substrate and a glass sub-structure, the method further comprising:
cutting the wide band-gap semiconductor wafer along the at least one trench structure to separate the plurality of semiconductor devices, wherein each of the glass sub-structures is in contact with a vertical surface of an edge of the semiconductor substrate after the cutting of the wide band-gap semiconductor wafer.
3 . The method of claim 1 , further comprising forming the least one opening of the glass structure after attaching the glass structure to the wide band-gap semiconductor wafer.
4 . The method of claim 3 , wherein forming the at least one opening comprises grinding a portion of the glass structure to expose at least one recess in the glass structure.
5 . The method of claim 3 , wherein forming the at least one opening comprises etching at least a portion of the glass structure to obtain at least a portion of the at least one opening.
6 . The method of claim 3 , wherein forming the at least one opening comprises heating the glass structure to a glass-transition temperature of the glass structure and exerting pressure on at least a part of the glass structure with an embossing pattern.
7 . The method of claim 1 , wherein the electrically conductive material of the at least one pad structure has a thickness larger than 5 μm.
8 . The method of claim 1 , wherein the plurality of semiconductor devices comprises a plurality of pad structures electrically connected to a plurality of doping regions of a plurality of semiconductor substrates of the plurality of semiconductor devices, wherein the plurality of pad structures are formed by forming the electrically conductive material within a plurality of openings of the glass structure, and wherein forming the electrically conductive material comprises forming an electrical connection between the plurality of pad structures.
9 . The method of claim 8 , further comprising removing the at least one electrical connection between the plurality of pad structures after forming the plurality of pad structures.
10 . The method of claim 8 , wherein at least portions of the electrical connection between the plurality of pad structures are located within a trench structure extending into the glass structure, the method further comprising grinding a portion of the glass structure to electrically disconnect the plurality of pad structures.
11 . The method of claim 1 , wherein forming the electrically conductive material comprises at least partially filling the at least one opening with an electrically conductive paste.
12 . The method of claim 1 , further comprising attaching a further glass structure to a backside of the wide band-gap semiconductor wafer and forming at least one electrically conductive structure electrically connected to a backside of the semiconductor substrate by forming electrically conductive material within at least one opening extending through the further glass structure.
13 . The method of claim 1 , further comprising separating the plurality of semiconductor devices by cutting only through electrically insulating material.
14 . The method of claim 1 , wherein the glass structure comprises at least one material selected from the group consisting of a borosilicate glass, a soda-lime glass, a float glass, a quartz glass, a porcelain, a polymer thermoplastic, a polymer glass, an acrylic glass, polycarbonate, polyethylene terephthalate, an undoped silica, a doped silica, a polynorbornene, polystyrene, a polycarbonate, a polyimide, a benzocyclobutene, and a parylene.
15 . The method of claim 1 , further comprising:
forming at least one trench structure extending into the wide band-gap semiconductor wafer between neighboring semiconductor devices of the plurality of semiconductor devices;
separating the wide band-gap semiconductor wafer into the plurality of semiconductor devices,
wherein the separating comprises cutting the wide band-gap semiconductor wafer and the glass structure along the at least one trench structure, and at least partially grinding a backside of the wide band-gap semiconductor wafer.
16 . The method of claim 1 , wherein reducing the thickness comprises grinding the wide band-gap semiconductor wafer and/or splitting-off a part of the wide band-gap semiconductor wafer using the cold split method.
17 . The method of claim 1 , further comprising:
forming the glass structure; and
attaching the glass structure to the wide band-gap semiconductor wafer after forming the glass structure.
18 . The method of claim 1 , wherein attaching the glass structure to the wide band-gap semiconductor wafer comprises hot embossing or anodic bonding.
19 . A method for forming semiconductor devices, the method comprising:
attaching a glass structure to a wide band-gap semiconductor wafer comprising a plurality of semiconductor devices;
forming at least one opening extending through the glass structure from a first outer surface of the glass structure to a second, opposite outer surface of the glass structure;
forming at least one pad structure by at least partially filling the at least one opening with electrically conductive material, such that a first end of the at least one pad structure is electrically connected to at least one doping region of a semiconductor substrate of the wide band-gap semiconductor wafer and a second, opposite end of the pad structure is exposed through the second, opposite outer surface of the glass structure;
forming at least one trench structure extending into the wide band-gap semiconductor wafer between neighboring semiconductor devices of the plurality of semiconductor devices; and
separating the wide band-gap semiconductor wafer into the plurality of semiconductor devices,
wherein the separating comprises cutting the wide band-gap semiconductor wafer and the glass structure along the at least one trench structure, and at least partially grinding a backside of the wide band-gap semiconductor wafer.
20 . The method of claim 19 , wherein the plurality of semiconductor devices each comprise a semiconductor substrate and a glass sub-structure, and wherein each of the glass sub-structures is in contact with a vertical surface of an edge of the semiconductor substrate after the cutting of the wide band-gap semiconductor wafer and the glass structure along the at least one trench structure.
21 . The method of claim 19 , wherein the plurality of semiconductor devices comprises a plurality of pad structures electrically connected to a plurality of doping regions of a plurality of semiconductor substrates of the plurality of semiconductor devices, wherein the plurality of pad structures are formed by forming the electrically conductive material within a plurality of openings of the glass structure, and wherein forming the electrically conductive material comprises forming an electrical connection between the plurality of pad structures.
22 . A method for forming semiconductor devices, the method comprising:
attaching a glass structure to a wide band-gap semiconductor wafer comprising a plurality of semiconductor devices;
forming at least one pad structure electrically connected to at least one doping region of a semiconductor substrate of the wide band-gap semiconductor wafer, by forming electrically conductive material within at least one opening extending through the glass structure;
reducing a thickness of the wide band-gap semiconductor wafer after attaching the glass structure, and
forming at least one trench structure extending partway but not completely through the wide band-gap semiconductor wafer between neighboring semiconductor devices of the plurality of semiconductor devices.