Transistor with heat dissipating means
View Patent ↗A semiconductor device having sufficiently high heat dissipation performance while inhibiting an increase in the area of a chip is provided. In semiconductor device 1 , a plurality of HBTs 20 and a plurality of diodes 30 are one-dimensionally and alternately arranged on semiconductor substrate 10 . Anode electrode 36 of diode 30 is connected to emitter electrode 27 of HBT 20 via common emitter wiring 42 . Diode 30 works as heat dissipating elements dissipating to semiconductor substrate 10 the heat transmitted through common emitter wiring 42 from emitter electrode 27 , and also works as a protection diode connected in parallel between an emitter and a collector of HBT 20.
1. A semiconductor device comprises:
a sub-collector layer formed on a semiconductor substrate,
a bipolar transistor formed by stacking a collector layer, a base layer and an emitter layer in this order on said sub-collector layer, and
a heat dissipating means dissipating heat generated in said bipolar transistor to said semiconductor substrate via a wiring connected with an emitter electrode of said bipolar transistor,
wherein said heat dissipating means is a pn junction diode composed of same layers as said sub-collector layer, collector layer and base layer of said bipolar transistor and spatially separated from said bipolar transistor,
wherein said collector layer of said bipolar transistor and said collector layer of said pn junction diode are electrically connected to a common collector electrode via said sub-collector layer, and
wherein one terminal of said diode is connected with said wiring, and
wherein a width of said wiring connecting between said emitter electrode of said bipolar transistor and said terminal of said diode is not less than the length of the emitter electrode.
2. The semiconductor device according to claim 1 , wherein said pn junction diode is a pin diode or p + n − n + diode having depleted n − layer.
3. The semiconductor device according to claim 2 , wherein said pin diode or p + n − n + diode is composed of p + layer having 1×10 19 cm −3 or more of dose, n − layer having 1×10 17 cm −3 or less of dose and n + layer with 1×10 18 cm −3 or more of dose.
4. The semiconductor device according to claim 1 , wherein said wiring interconnects electrodes having the same function on a plurality of said bipolar transistors.
5. The semiconductor device according to claim 4 , wherein said electrodes having the same function are emitter electrodes.
6. The semiconductor device according to claim 1 , further comprising:
a unit bipolar transistor comprising a plurality of said bipolar transistor; and
wherein said heat dissipating means is formed between adjacent unit bipolar transistors.
7. The semiconductor device according to claim 6 , wherein a plurality of said unit bipolar transistors is formed in a specific arrangement on said semiconductor substrate; and
wherein said heat dissipating means is also formed on at least one peripheral side of said specific arrangement.
8. The semiconductor device according to claim 6 , wherein a plurality of said unit bipolar transistors is formed in a specific arrangement on said semiconductor substrate; and
wherein the area of a region provided with said heat dissipating means situated at a relatively central part of said specific arrangement is larger than the area of a region provided with said heat dissipating means situated at a relatively peripheral part of said specific arrangement.
9. The semiconductor device according to claim 8 , wherein the area of said heat dissipating means depends on the width of said heat dissipating means in a direction parallel to said specific arrangement.
10. The semiconductor device according to claim 8 , wherein the area of said heat dissipating means depends on the length of said heat dissipating means in a direction perpendicular to said certain arrangement.
11. The semiconductor device according to claim 8 , wherein the area of said heat dissipating means depends on both width and length of said heat dissipating means.
12. The semiconductor device according to claim 8 , wherein a plurality of said unit bipolar transistors are arranged in a specific direction and said wiring over the region of said heat dissipating means is extended in a direction perpendicular to said specific direction.
13. The semiconductor device according to claim 12 , wherein said wiring is connected to a pad electrode at a terminal of said extended wiring.
14. The semiconductor device according to claim 1 , wherein a plurality of said unit bipolar transistors are formed in a specific arrangement on said semiconductor substrate;
wherein said wiring is extended to at least one direction perpendicular to said specific arrangement; and
wherein said heat dissipating means is formed under said extended wiring.
15. The semiconductor device according to claim 1 , wherein said wiring is formed on an insulating film covering said bipolar transistor and said heat dissipating means, and is connected to the emitter electrode of said bipolar transistor and to the terminal of said heat dissipating means via openings provided in said insulating film.