Patent ID: 6121640
Filing Date: 2000-09-19
Classification: H01L

Abstract:
A monolithic integrated device formed on a semiconductor material substrate having a first conductivity type, which device comprises:an epitaxial layer formed on the substrate and having the first conductivity type;a first transistor of the bipolar type having a base region with a second conductivity type and including a first buried region formed in the epitaxial layer, and having a first diffused region extending from the first buried region to contact a top surface of the device through a surface contact region with a high concentration of dopant material, said first transistor also having an emitter region with the first conductivity type, embedded in the base region, and including a second buried region formed on the first buried region and a second diffused region, with a high concentration of dopant material, which extends from the second buried region to contact the top surface of the device;a second transistor of the MOS type having a drain region included within the emitter region of the first transistor, said drain region incorporating a third diffused region with a high concentration of dopant material and the first conductivity type which includes a source region of the second transistor; anda protection structure formed by the surface contact region overlapping at least one of the diffused regions with a high concentration of dopant material to provide a low breakdown voltage junction of the Zener type.