1. A transistor comprising:
a base layer comprising:
a first doping layer that is doped with a trivalent substance;
a second doping layer adjacent to the first doping layer and having a lower concentration of the trivalent substance than the first doping layer; and
a third doping layer adjacent to the second doping layer and having a higher concentration of the trivalent substance than the second doping layer;
wherein the first doping layer and the second doping layer are counter-doped with a pentavalent substance from an emitter region of the transistor; and
wherein the base layer comprises carbon atoms having a concentration greater than 1\xd71018 cm\u22123.
2. The transistor of claim 1, wherein the second doping layer and the third doping layer are doped with germanium.
3. The transistor of claim 2, wherein a concentration of germanium in the second doping layer and the third doping layer decreases from a high point at a collector region of the transmitter to a low point in the second layer.
4. The transistor of claim 2, wherein a decrease in the concentration of germanium from the high point to the low point is substantially constant.
5. A transistor comprising:
an emitter region;
a collector; and
a base layer having a base contact, the base layer comprising:
an intrinsic region between the emitter region and the collector;
an extrinsic region between the intrinsic region and the base contact;
a first doping layer that is doped with a trivalent substance, and that extends into the extrinsic region;
a second doping layer that is doped with a trivalent substance, and that is between the first doping layer and the collector, the first and second doping layers being counter-doped with a pentavalent substance from the emitter region; and
a third doping layer that is doped with a trivalent substance, and that is between the second doping layer and the collector;
wherein the base layer comprises carbon atoms having a concentration greater than 1\xd71018 cm\u22123; and
wherein a concentration of trivalent substance in the second doping layer is less than a concentration of trivalent substance in the first doping layer, and the concentration of trivalent substance in the second doping layer is less than a concentration of trivalent substance in the third doping layer.
6. The transistor of claim 5, wherein the trivalent substance comprises boron.
7. The transistor of claim 5, wherein the first doping layer comprises at least 30% of a total amount of a doping substance in the base layer.
8. The transistor of claim 6, wherein the first doping layer comprises at least 30% of a total amount of a doping substance in the base layer.
9. The transistor of claim 5, wherein the second doping layer and the third doping layer are doped with germanium.
10. The transistor of claim 9, wherein:
a concentration of germanium in the second doping layer and the third doping layer decreases from a high point at the collector to a low point in the second layer; and
a decrease in the concentration of germanium from the high point to the low point is substantially constant.
11. The transistor of claim 9, wherein the trivalent substance comprises boron.
12. The transistor of claim 9, wherein the pentavalent substance comprises arsenic having a concentration of between 1\xd71020 cm\u22123 and 1\xd71021 cm\u22123.
13. A transistor comprising:
an emitter region;
a collector; and
a base layer having a base contact, the base layer comprising:
an intrinsic region between the emitter region and the collector;
an extrinsic region between the intrinsic region and the base contact;
a first doping layer that is doped with a trivalent substance, that extends into the extrinsic region, and that is counter-doped with a pentavalent substance from the emitter region, wherein the first doping layer comprises a concentration of the trivalent substance that is between 1\xd71018 cm\u22123 and 5\xd71020 cm\u22123;
a second doping layer that is doped with the trivalent substance, that extends into the extrinsic region, and that is counter-doped, at least part-way through, with a pentavalent substance from the emitter region, wherein the second doping layer comprises a concentration of the pentavalent substance that is between 1\xd71020 cm\u22123 and 1\xd71021 cm\u22123, wherein the second doping layer comprises a concentration of the trivalent substance that is between 1\xd71018 cm\u22123 and 1\xd71019 cm\u22123; and
a third doping layer that is doped with the trivalent substance, the third doping layer being adjacent to the collector, wherein the third doping layer comprises a concentration of the dopant that is between 5\xd71018 cm\u22123 and 1\xd71020;
wherein the second doping layer is between the first doping layer and the third doping layer, and wherein the second doping layer has a lower concentration of the trivalent substance than both the first doping layer and the third doping layer;
wherein the first doping layer, the second doping layer, and the third doping layer are separated from the emitter region by a portion of the base layer; and
wherein the base layer comprises carbon atoms having a concentration greater than 1\xd71018 cm\u22123.
The claims below are in addition to those above.
All refrences to claim(s) which appear below refer to the numbering after this setence.
1. A compound represented by the formula I:
(wherein, R2 and R3, each independently, represent lower alkoxy groups; R5 represents a benzyl group or a tert-butyl group; and Ar represents a monocyclic or bicyclic aryl or heteroaryl group optionally having substituent(s) selected from the group consisting of lower alkyl group(s), lower alkoxy group(s), halogen atom(s), halogenated lower alkyl group(s), hydroxyl group(s), carboxyl group(s), lower alkoxy carbonyl group(s), nitro group(s), amino group(s), lower alkylamino group(s), cyano group(s) and methylenedioxy group(s)), or a pharmaceutically acceptable salt thereof.
2. The compound or pharmaceutically acceptable salt thereof according to claim 1 wherein Ar is a phenyl group, a naphthyl group, a furyl group, a thienyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazolyl group, a pyrrolyl group, a pyrimidinyl group, a quinolyl group, a quinoxalinyl group, an isoquinolyl group, a pyrazinyl group, an indolyl group, a benzothiazolyl group or a benzimidazolyl group, each of these groups optionally having substituent(s) selected from the group consisting of lower alkyl group(s), lower alkoxy group(s), halogen atom(s), halogenated lower alkyl group(s), hydroxyl group(s), carboxyl group(s), lower alkoxycarbonyl group(s), nitro group(s), amino group(s), lower alkylamino group(s), cyano group(s) and methylenedioxy group(s).
3. The compound or pharmaceutically acceptable salt thereof according to claim 2 wherein Ar is a phenyl group, a furyl group, a thienyl group, a thiazolyl group, an isothiazolyl group, an oxazolyl group, an isoxazolyl group, a pyridinyl group, a pyrazolyl group, a pyrrolyl group, a quinolyl group, a quinazolinyl group, an isoquinolyl group or a pyrazinyl group, each of these groups optionally having substituent(s) selected from the group consisting of lower alkyl group(s), lower alkoxy group(s), halogen atom(s), halogenated lower alkyl group(s), hydroxyl group(s), carboxyl group(s), lower alkoxycarbonyl group(s), nitro group(s), amino group(s), lower alkylamino group(s), cyano group(s) and methylenedioxy group(s).
4. The compound according to claim 2 wherein Ar is a phenyl group, a furyl group, a thienyl group, a thiazolyl group, pyridinyl group, a quinolyl group or a pyrrolyl group, each of these groups optionally having substituent(s) selected from the group consisting of lower alkyl group(s), lower alkoxy group(s), halogen atom(s), halogenated lower alkyl group(s), hydroxyl group(s), carboxyl group(s), lower alkoxycarbonyl group(s), intro group(s), amino group(s), lower alkylamino group(s), cyano group(s) and methylenedioxy group(s).
5. The compound or pharmaceutically acceptable salt thereof according to claim 2 wherein R2 and R3 are methoxy groups.
6. A pharmaceutical composition containing a therapeutically effective amount of at least one of the compounds and pharmaceutically acceptable salts thereof according to one of claims 1 to 5 as an active ingredient, and a pharmaceutically acceptable carrier.