Ingaas semiconductor structures

Claim 2

A semiconductor device comprising: a semiconductor substrate having a first major surface on which semiconductor devices are to be formed, and a second major surface; an epitaxially grown etch stop first layer disposed on said first major surface; a second layer composed of semiconductor material disposed epitaxially on said etch stop layer and including a dopant species provided through said second major surface and through said etch stop layer, thereby forming doped regions in said second layer of semiconductor material and respectively associated self-aligned guard rings in said etch stop layer, the diffusion rate of said dopant species in said etch stop layer being less than the diffusion rate of said dopant species in said second layer, and; apertures in said substrate extending to said etch stop layer, said dopant species being introduced into said etch stop layer and into said second layer via apertures.

Claim 3

A device as defined in claim 1 wherein said substrate is semi-insulating.

Claim 4

A device as defined in claim 1, wherein said substrate is Fe:InP.

Claim 5

A device as defined in claim 1 wherein said etch stop layer is InGaAsP.

Claim 6

A device as defined in claim 1 wherein said second layer composed of semiconductor material comprises InP.

Claim 7

A device as defined in claim 1, further comprising a third layer composed of semiconductor material disposed on said second layer of semiconductor material.

Claim 8

A device as defined in claim 6, wherein said third layer is composed of InGaAs.

Claim 9

A device as defined in claim 6, further comprising a fourth layer of semiconductor material disposed on said third layer of semiconductor material.

Claim 10

A device as defined in claim 8, wherein said fourth layer is composed of heavily doped InGaAs.

Claim 11

A device as defined in claim 1, wherein said dopant species provided in said second layer comprises Zn.

Claim 12

Semiconductor apparatus comprising: a substrate having first and second major surfaces, an etch stop layer on said first major surface, a layer of semiconductor material on said etch stop layer, first devices including said layer of semiconductor material formed overlying said first major surface, apertures in said substrate extending from said second major surface to but not through said etch stop layer, whereby a dopant species introduced into said apertures from said second major surface must traverse said etch stop layer to enter said layer of semiconductor material, and a dopant species in said etch stop layer and in said layer of semiconductor material in alignment with each of said apertures, the diffusion rate of said dopant species in said etch stop layer being less than the diffusion rate of said dopant species in said layer of semiconductor material, whereby a doped region is formed in said layer of semiconductor material in alignment with each aperture and a respectively associated self-aligned doped guard-ring region is formed in said etch stop layer.

Claim 13

Semiconductor apparatus comprising: a substrate having first and second major surfaces, an etch stop layer on said first major surface, a layer of semiconductor material on said etch stop layer, first devices including said layer of semiconductor material formed overlying said first major surface, apertures in said substrate extending from said second major surface to but not through said etch stop layer, whereby a dopant species introduced into said apertures from said second major surface must traverse said etch stop layer to enter said layer of semiconductor material, and a dopant species in said etch stop layer and in said layer of semiconductor material in alignment with each of said apertures, the diffusion rate of said dopant species in said etch stop layer being less than the diffusion rate of said dopant species in said layer of semiconductor material, whereby a doped region is formed in said layer of semiconductor material in alignment with each aperture and a respectively associated self-aligned doped guard-ring region is formed in said etch stop layer.

Claim 14

Apparatus as in claim 11 further including a layer of semiconductor material in the second major surface of said substrate, and second devices formed in said layer of semiconductor material that is formed in second major surface of said substrate.

Claim 15

Apparatus as in claim 12 further including means interconnecting said first and second devices.

Claim 16

Apparatus as in claim 13 wherein said first devices comprise avalanche photodiodes and said second devices comprise junction field-effect transistors.