Production of a three-layer diac with five-layer edge regions having middle region thinner at center than edge

Claim 1

A METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE, COMPRISING THE STEPS OF: A. PROVIDING A SEMICONDUCTOR BODY HAVING A FIRST CONDUCTIVITY TYPE, SAID BODY HAVING FIRST AND SECOND MAJOR SURFACES: B. PROVIDING AT SAID MAJOR SURFACES RESPECTIVE FIRST AND SECOND REGIONS OF A SECOND OPPOSITE CONDUCTIVITY TYPE, EACH OF SAID FIRST AND SECOND REGIONS COMPRISING FIRST AND SECOND PORTIONS, SAID STEP OF PROVIDING SAID REGIONS BEING EXECUTED SUCH THAT SAID FIRST PORTIONS EXCEED SAID SECOND PORTIONS IN THICKNESS AND INCLUDE THEREBETWEEN FIRST CONDUCTIVITY TYPE FIRST PARTS OF SAID SEMICONDUCTOR BODY AND FURTHER SUCH THAT SAID SECOND PORTIONS INCLUDE THEREBETWEEN FIRST CONDUCTIVITY TYPE SECOND PARTS OF SAID SEMICONDUCTOR BODY INDIVIDUALLY HAVING A THICKNESS EXCEEDING THOSE OF SAID PARTS: C. PROVIDING AT RESPECTIVE SURFACE REGIONS OF ONLY SAID SECOND PORTIONS THIRD SEMICONDUCTOR REGIONS HAVING SAID FIRST CONDUCTIVITY TYPE, SAID THIRD REGION DEFINING RESPECTIVE THIRD AND FOURTH SURFACES TOGETHER WITH SAID FIRST AND SECOND REGIONS RESPECTIVELY: AND D. PROVIDING ELECTRICAL CONNECTION MEANS AT SAID THIRD AND FOURTH SURFACES.

Claim 2

A METHOD OF MANUFACTURING A SEMICONDUCTOR DEVICE, COMPRISING THE STEPS OF: A. PROVIDING A SEMICONDUCTOR BODY HAVING A FIRST CONDUCTIVITY TYPE, SAID BODY HAVING FIRST AND SECOND MAJOR SURFACES: B. PROVIDING AT SAID MAJOR SURFACES RESPECTIVE FIRST AND SECOND REGIONS OF A SECOND OPPOSITE CONDUCTIVITY TYPE, EACH OF SAID FIRST AND SECOND REGIONS COMPRISING FIRST AND SECOND PORTIONS, SAID STEP OF PROVIDING SAID REGIONS BEING EXECUTED SUCH THAT SAID FIRST PORTIONS EXCEED SAID SECOND PORTIONS IN THICKNESS AND INCLUDE THEREBETWEEN FIRST CONDUCTIVITY TYPE FIRST PARTS OF SAID SEMICONDUCTOR BODY AND FURTHER SUCH THAT SAID SECOND PORTIONS INCLUDE THEREBETWEEN FIRST CONDUCTIVITY TYPE SECOND PARTS OF SAID SEMICONDUCTOR BODY INDIVIDUALLY HAVING A THICKNESS EXCEEDING THOSE OF SAID PARTS: C. PROVIDING AT RESPECTIVE SURFACE REGIONS OF ONLY SAID SECOND PORTIONS THIRD SEMICONDUCTOR REGIONS HAVING SAID FIRST CONDUCTIVITY TYPE, SAID THIRD REGION DEFINING RESPECTIVE THIRD AND FOURTH SURFACES TOGETHER WITH SAID FIRST AND SECOND REGIONS RESPECTIVELY: AND D. PROVIDING ELECTRICAL CONNECTION MEANS AT SAID THIRD AND FOURTH SURFACES.

Claim 3

A method of manufacturing a semiconductor device, comprising the steps of: a. providing a plate-shaped semiconductor body comprising first and second surfaces and having a first conductivity type; b. providing on said first and second surfaces a glass layer comprising a first doping material of a second opposite conductivity type, said layer comprising areas only partially covering said first and second surfaces such that portions of said first and second surfaces located between said areas are exposed; c. simultaneously diffusing said first doping material into the covered portions of said first and second surfaces to a first depth in said semiconductor body and diffusing into said exposed surface portions of said semiconductor body both a second doping material of said second conductivity type having a lower surface concentration than said first doping material and a third doping material of said first conductivity type, said third doping material being characterized by being retained by said glass layer and diffused to a second depth in said body less than said first depth and having a higher surface concentration and a lower diffusion coefficient than said second doping material, said second doping material being diffused in said body to a third depth intermediate said first and second depths, so as to form at only a lateral region of said body a five-layer structure having regions of alternating conductivity type that form plural p,n junctions and to form at a central region of said body a three-layer structure having alternating conductivity type; d. removing material at said lateral region of said body so as to expose said p,n junctions; and e. providing electrodes at opposite faces of the structure thus produced.

Claim 4

A method of manufacturing a semiconductor device, comprising the steps of: a. providing a plate-shaped semiconductor body comprising first and second surfaces and having a first conductivity type; b. providing on said first and second surfaces a glass layer comprising a first doping material of a second opposite conductivity type, said layer comprising areas only partially covering said first and second surfaces such that portions of said first and second surfaces located between said areas are exposed; c. simultaneously diffusing said first doping material into the covered portions of said first and second surfaces to a first depth in said semiconductor body and diffusing into said exposed surface portions of said semiconductor body both a second doping material of said second conductivity type having a lower surface concentration than said first doping material and a third doping material of said first conductivity type, said third doping material being characterized by being retained by said glass layer and diffused to a second depth in said body less than said first depth and having a higher surface concentration and a lower diffusion coefficient than said second doping material, said second doping material being diffused in said body to a third depth intermediate said first and second depths, so as to form at only a lateral region of said body a five-layer structure having regions of alternating conductivity type that form plural p,n junctions and to form at a central region of said body a three-layer structure having alternating conductivity type; d. removing material at said lateral region of said body so as to expose said p,n junctions; and e. providing electrodes at opposite faces of the structure thus produced.