Abstract: A method for fabricating an upright photovoltaic cell comprises growing one or more epitaxial layers on a substrate, thereby forming a diffused active junction on the substrate and one more additional active junctions above the diffused active junction. The method further comprises selectively etching an areal region of the one or more epitaxial layers, thereby forming a mesa on the substrate and exposing a substrate-contact region parallel to the areal region at a base of the mesa. The method further comprises depositing contact material onto the substrate-contact region, to form the first contact, and concertedly onto a mesa-contact region of the mesa, to form the second contact.

Abstract: The disclosure provides for a direct wafer bonding method including providing a bonding layer upon a first and second wafer, and directly bonding the first and second wafers together under heat and pressure. The method may be used for directly bonding an GaAs-based, InP-based, GaP-based, GaSb-based, or Ga(In)N-based device to a GaAs device by introducing a highly doped (Al)(Ga)InP(As)(Sb) layer between the devices. The bonding layer material forms a bond having high bond strength, low electrical resistance, and high optical transmittance.

Abstract: The disclosure provides for a direct wafer bonding method including providing a bonding layer upon a first and second wafer, and directly bonding the first and second wafers together under heat and pressure. The method may be used for directly bonding an GaAs-based, InP-based, GaP-based, GaSb-based, or Ga(In)N-based device to a GaAs device by introducing a highly doped (Al)(Ga)InP(As)(Sb) layer between the devices. The bonding layer material forms a bond having high bond strength, low electrical resistance, and high optical transmittance.

Abstract: The disclosure provides for a direct wafer bonding method including providing a bonding layer upon a first and second wafer, and directly bonding the first and second wafers together under heat and pressure. The method may be used for directly bonding an GaAs-based, InP-based, GaP-based, GaSb-based, or Ga(In)N-based device to a GaAs device by introducing a highly doped (Al)(Ga)InP(As)(Sb) layer between the devices. The bonding layer material forms a bond having high bond strength, low electrical resistance, and high optical transmittance.

Abstract: The disclosure provides for a direct wafer bonding method including providing a bonding layer upon a first and second wafer, and directly bonding the first and second wafers together under heat and pressure. The method may be used for directly bonding an GaAs-based, InP-based, GaP-based, GaSb-based, or Ga(In)N-based device to a GaAs device by introducing a highly doped (Al)(Ga)InP(As)(Sb) layer between the devices. The bonding layer material forms a bond having high bond strength, low electrical resistance, and high optical transmittance.

Abstract: A method of forming an air gap or gaps within solid structures and specifically semiconductor structures to reduce capacitive coupling between electrical elements such as metal lines, wherein a sacrificial material is used to occupy a closed interior volume in a semiconductor structure is disclosed. The sacrificial material is caused to decompose into one or more gaseous decomposition products which are removed, in one embodiment by diffusion, through an overcoat layer. The decomposition of the sacrificial material leaves an air gap or gaps at the closed interior volume previously occupied by the sacrificial material. The air gaps may be disposed between electrical leads to minimize capacitive coupling therebetween. Also disclosed are methods of forming multi-level air gaps and methods or forming over-coated conductive lines or leads wherein a portion of the overcoating is in contact with at least one air gap.

Abstract: A method of forming an air gap or gaps within solid structures and specifically semiconductor structures to reduce capacitive coupling between electrical elements such as metal lines, wherein a sacrificial material is used to occupy a closed interior volume in a semiconductor structure is disclosed. The sacrificial material is caused to decompose into one or more gaseous decomposition products which are removed, in one embodiment by diffusion, through an overcoat layer. The decomposition of the sacrificial material leaves an air gap or gaps at the closed interior volume previously occupied by the sacrificial material. The air gaps may be disposed between electrical leads to minimize capacitive coupling therebetween.

Abstract: A method of forming an air gap or gaps within solid structures and specifically semiconductor structures to reduce capacitive coupling between electrical elements such as metal lines, wherein a sacrificial material is used to occupy a closed interior volume in a semiconductor structure is disclosed. The sacrificial material is caused to decompose into one or more gaseous decomposition products which are removed, in one embodiment by diffusion, through an overcoat layer. The decomposition of the sacrificial material leaves an air gap or gaps at the closed interior volume previously occupied by the sacrificial material. The air gaps may be disposed between electrical leads to minimize capacitive coupling therebetween. Also disclosed are methods of forming multi-level air gaps and methods or forming over-coated conductive lines or leads wherein a portion of the overcoating is in contact with at least one air gap.

Abstract: A method of forming an air gap or gaps within solid structures and specifically semiconductor structures to reduce capacitive coupling between electrical elements such as metal lines, wherein a sacrificial material is used to occupy a closed interior volume in a semiconductor structure is disclosed. The sacrificial material is caused to decompose into one or more gaseous decomposition products which are removed, in one embodiment by diffusion, through an overcoat layer. The decomposition of the sacrificial material leaves an air gap or gaps at the closed interior volume previously occupied by the sacrificial material. The air gaps may be disposed between electrical leads to minimize capacitive coupling therebetween.