Semiconductor device with positively beveled junctions and process for its manufacture

Claim 2

A process for beveling a semiconductive element containing a first layer of a first conductivity type, a second layer of an opposite conductivity type located adjacent the first layer and forming a first junction therewith, and a third layer of the first conductivity type lying adjacent the second layer and forming a second junction therewith, the second layer''s width as measured thereacross between the first and second junctions being greater than the corresponding width of either of the first and third layers, the second layer exhibiting a higher resitivity than either of the first and third layers, comprising forming a first edge surface peripherally encompassing the semiconductive element, intersecting the first junction at an acute angle to form a positive bevel angle therewith, and extending transversely across the second layer to intersect the second junction to form a negative bevel angle therewith, and relieving a portion of the semiconductive element along the first edge surface adjacent the second junction to form a second edge surface positively beveled across the second junction and lying entirely inwardly of the first edge surface, and also to form a third edge surface extending inwardly from said first edge surface between said first and second junctions to join with said second edge surface, said third edge surface comprising a concave portion and a horizontal portion, said concave portion extending from said second edge surface to said horizontal portion, said horizontal portion extending generally parallel to said junctions from said concave portion to said first edge surface, said second and third edge surfaces diverging outwardly from the junction thereof so as to produce a relatively wide divergence.

Claim 3

A process according to claim 1 in which the portion of the semiconductive element adjacent the second junction is relieved by grit blasting.

Claim 4

A process according to claim 1 in which each of said edge surfaces are formed by grit blasting.

Claim 5

A process for beveling a semiconductive element containing a first layer of a first conductivity type, a second layer of an opposite conductivity type located adjacent the first layer and forming a first junction therewith, and a third layer of the first conductivity type lying adjacent the second layer and forming a second junction therewith, the second layer''s width as measured thereacross between the first and second junctions being greater than the corresponding width of either the first and third layers, the second layer exhibiting a higher resistivity than either of the first and third layers, comprising forming a first frustum surface peripherally encompassing the semiconductive element intersecting the first junction at an acute angle to form a positive bevel angle therewith and extending transversely across the second layer to intersect the second junction to form a negative bevel angle therewith, and relieving a portion of the semiconductive element along the first frustum surface adjacent the second junction to form a second frustum surface positively beveled across the second junction and lying entirely inwardly of the first frustum surface, and also to form a third surface extending inwardly from said first frustum surface between said first and second junctions to join with said second frustum surface, said third surface comprising a concave portion and a horizontal portion, said concave portion extending from said second frustum surface to said horizontal portion, said horizontal portion extending substantially parallel to said junctions from said concave portion to said first frustum surface, said second frustum surface and said third surface diverging outwardly from the junction thereof so as to produce a relatively wide divergence.

Claim 6

A process for beveling a semiconductive element containing a first layer of a first conductivity type, a second layer of an opposite conductivity type located adjacent the first layer and forming a first junction therewith, and a third layer of the first conductivity type lying adjacent the second layer and forming a second junction therewith, the second layer''s width as measured thereacross between the first and second junctions being greater than the corresponding width of either the first and third layers, the second layer exhibiting a higher resistivity than either of the first and third layers, comprising forming a first frustum surface peripherally encompassing the semiconductive element intersecting the first junction at an acute angle to form a positive bevel angle therewith and extending transversely across the second layer to intersect the second junction to form a negative bevel angle therewith, and relieving a portion of the semiconductive element along the first frustum surface adjacent the second junction to form a second frustum surface positively beveled across the second junction and lying entirely inwardly of the first frustum surface, and also to form a third surface extending inwardly from said first frustum surface between said first and second junctions to join with said second frustum surface, said third surface comprising a concave portion and a horizontal portion, said concave portion extending from said second frustum surface to said horizontal portion, said horizontal portion extending substantially parallel to said junctions from said concave portion to said first frustum surface, said second frustum surface and said third surface diverging outwardly from the junction thereof so as to produce a relatively wide divergence.