SEMICONDUCTOR DEVICE WITH INBUILT PROTECTION FROM OVERVOLTAGE Russian patent published in 2006 - IPC H01L29/74 

FIELD: engineering of semiconductor devices with inbuilt protection from disruption in case of overvoltage in closed state, namely, engineering of dinistors and thyristors, including symmetrical ones.

SUBSTANCE: semiconductor device with inbuilt protection from overvoltage is made on basis of silicon plate of n-type of electric conductivity with two main surfaces, positioned on opposite sides of aforementioned plate. Device contains, on the side of first main surface, emitter n-layer, diffusion base p-layer with etched recess, forming a collector p-n transition in the source silicon plate and having a portion with high gradient of concentration of acceptor admixture, positioned below the etched recess, emitter p-layer, formed on the side of second main surface of plate, electrodes of anode, cathode and controlling electrode. Diffusion base p-layer contains below aforementioned etched recess the acceptor admixture of first type, outside the recess - acceptor admixtures of both first and second types, having different diffusion coefficients, while depth h [micrometers] of etched recess satisfies the condition: 1,1≥h/(x_j2-x_j1)≥0,8, where x_j1 and x_j2 [micrometers] - depth of diffusion of acceptor admixtures of first and second types, respectively.

EFFECT: decreased relative spreading of values of device switching voltage U_BO, simplified technology of its manufacture, increased percentage of production of non-defective devices.

1 tbl, 4 dwg