Semiconductor device having an extrinsic base region with a monocrystalline region and method therefor

A bipolar transistor device comprising:

• a semiconductor substrate;
• a first isolation region formed within the semiconductor substrate;
• a collector region having a first width formed within the semiconductor substrate, the collector region having an upper surface and a collector sidewall;
• an intrinsic base region having a second width, disposed over the collector region, wherein the first width is greater than the second width;
• a dielectric region formed over at least a portion of the semiconductor substrate and over the collector sidewall;
• an intrinsic base region having a second width, disposed over the collector region, wherein the first width is greater than the second width;
• an extrinsic base region having an upper surface and formed over the collector region and electrically coupled to the intrinsic base region, wherein the extrinsic base region includes a monocrystalline region coupled to the intrinsic base region and a polycrystalline region coupled to the monocrystalline region, wherein at least a portion of the monocrystalline region is formed above and laterally outside the intrinsic base region formed from monocrystalline material;
• and
• an emitter region formed over the intrinsic base region;
• wherein a portion of a base link region formed within the base cavity is monocrystalline and is coupled to the monocrystalline region of the extrinsic base region.

A method of forming a bipolar transistor device, the method comprising:

• forming an isolation region within a semiconductor substrate;
• forming a collector region having a first width laterally adjacent the isolation region within the semiconductor substrate, wherein the collector region includes an upper surface and a collector sidewall;
• forming an intrinsic base region having a second width over the collector region, wherein the first width is greater than the second width;
• forming a dielectric region over at least a portion of the semiconductor substrate and over the collector sidewall;
• forming an extrinsic base region having an upper surface and formed over the collector region and electrically coupled to the intrinsic base region, wherein the extrinsic base region includes a monocrystalline region coupled to the intrinsic base region and a polycrystalline region coupled to the monocrystalline region, wherein at least a portion of the monocrystalline region is formed above and outside the intrinsic base region formed from monocrystalline material;
• forming a base cavity and forming the intrinsic base region and a base link region in the base cavity, wherein a portion of the base link region is monocrystalline;
• and
• forming an emitter region over the intrinsic base region.

A method of forming a bipolar transistor device, the method comprising:

• forming an isolation region within a semiconductor substrate;
• forming a collector region having a first width laterally adjacent the isolation region within the semiconductor substrate, wherein the collector region includes an upper surface and a collector sidewall;
• forming an intrinsic base region having a second width over the collector region, wherein the first width is greater than the second width;
• forming a dielectric region over at least a portion of the semiconductor substrate and over the collector sidewall;
• forming an extrinsic base region having an upper surface and formed over the collector region and electrically coupled to the intrinsic base region, wherein the extrinsic base region includes a monocrystalline region coupled to the intrinsic base region and a polycrystalline region coupled to the monocrystalline region, wherein forming the monocrystalline region includes performing a pre-amorphization implant;
• and
• forming an emitter region over the intrinsic base region.