Bipolar transistor with divided base and emitter regions
View Patent ↗A modified bipolar transistor defined for providing a larger emitter current than a basic emitter current from a basic bipolar transistor is provided. The modified transistor has an improved emitter structure comprising plural divided sub-emitter regions electrically isolated and spatially separated from each other. The plural divided sub-emitter regions may typically have a uniform emitter size identical with a basic emitter size of the basic bipolar transistor. A set of the plural divided sub-emitter regions provides an intended emitter current distinctly larger than the basic emitter current by a highly accurate direct current amplification factor corresponding to an intended emitter-size magnification factor.
1. A device structure comprising:
an isolation region completely surrounding a single continuous collector region of only a single transistor;
a discontinuous base region located within said collector region, said discontinuous base region comprising plural divided sub-base regions spatially separated from each other;
a base electrode contact region located within the base region, said base electrode contact region comprising plural divided base electrode contact sub-regions spatially separated from each other; and
an emitter region located within the discontinuous base region, said emitter region comprising plural divided sub-emitter regions spatially separated from each other,
said plural divided sub-emitter regions being also spatially separated, at least in a plan view first direction, from the base electrode contact region,
said plural divided sub-emitter regions having respective sub-emitter lengths defined in a plan view second direction perpendicular to said first direction, and a total sum of said respective sub-emitter lengths corresponds to a predetermined effective emitter length defined in said second direction for an intended emitter current from said emitter region,
wherein said respective sub-emitter lengths are within a range of 0.8 times to 1.2 times of a predetermined basic emitter length defined as a unit emitter length for a basic emitter current as a unit emitter current,
wherein said plural divided sub-emitter regions are aligned in said second direction as a second-direction grouping,
wherein the plural base electrode contact sub-regions are aligned in said second direction and in parallel to said second-direction grouping of said plural divided sub-emitter regions, and said plural divided sub-emitter regions have a uniform distance from said plural base electrode contact sub-regions over said second direction, and
wherein said plural divided sub-base regions are aligned in said second direction, and
a set of one of said plural base electrode contact sub-regions and one of said plural divided sub-emitter regions is provided in each of said plural divided sub-base regions.
2. The device structure of claim 1 , wherein,
within each sub-base region, all said divided sub-emitter regions are aligned in registration in the first direction with said one base electrode contact sub-region and none of said divided sub-emitter regions are aligned in registration with said one base electrode contact in the second direction, and
further comprising a collector within said collector region and in registration in the first direction with each sub-base region.
3. A device structure comprising:
an isolation region completely surrounding a single continuous collector region of only a single transistor,
the single transistor having a plan view first direction and a plan view second direction, the second direction being coplanar and perpendicular to the first direction;
a base region located within said collector region;
a base electrode contact region located with the base region, said base electrode contact region comprising plural divided base electrode contact sub-regions spatially separated from each other and aligned in the second direction; and
an emitter region located within the base region,
said emitter region comprising plural divided sub-emitter regions spatially separated from each other,
said plural divided sub-emitter regions being also spatially separated, at least in the first direction, from the base electrode contact region, and
said plural divided sub-emitter regions having respective sub-emitter lengths defined in the second direction, and a total sum of said respective sub-emitter lengths corresponds to a predetermined effective emitter length defined in said second direction for an intended emitter current from said emitter region, wherein,
said respective sub-emitter lengths are within a range of 0.8 times to 1.2 times of a predetermined basic emitter length defined as a unit emitter length for a basic emitter current as a unit emitter current,
said plural divided sub-emitter regions are aligned in a matrix,
plural first direction groupings extend in said first direction,
each of said plural first direction groupings comprising a set of said at least one divided base electrode contact sub-region located intermediate two of said plural divided sub-emitter regions,
in each of said plural first direction groupings, said one divided base electrode contact region and each of said plural divided sub-emitter regions are adjacent to each other but spatially separated from each other at a uniform distance, and
said plural first direction groupings are aligned in the second direction.
4. The device structure of claim 3 , wherein, within each sub-base region, all said divided sub-emitter regions are aligned in registration in the first direction with said one base electrode contact subregion and none of said divided sub-emitter regions are aligned in registration with said one base electrode contact in the second direction, and
further comprising a collector contact within said collector region and in registration in the first direction with each sub-base region.