A method is presented for forming a monolithically integrated semiconductor device. The method includes forming a first device including first hydrogenated silicon-based contacts formed on a first portion of a semiconductor material of an insulating substrate and forming a second device including second hydrogenated silicon-based contacts formed on a second portion of the semiconductor material of the insulating substrate. Source and drain contacts of the first device are formed before a gate contact of the first device and a gate contact of the second device is formed before the emitter and collector contacts of the second device. The first device can be a heterojunction field effect transistor (HJFET) and the second device can be a (heterojunction bipolar transistor) HBT. The HJFET and the HBT are integrated in a neuronal circuit and create negative differential resistance by forming a lambda diode.

Disclosed examples provide fabrications methods and integrated circuits with back ballasted NPN bipolar transistors which include an n-type emitter in a P doped region, a p-type base with a first side facing the emitter, and an n-type collector laterally spaced from a second side of the base, where the collector includes a first side facing the second side of the base, an opposite second side, a silicided first collector portion and a silicide blocked second collector portion covered with a non-conductive dielectric that extends laterally between the first collector portion and the second side of the collector to provide back side ballasting for lateral breakdown and low current conduction via a deep N doped region while the vertical NPN turns on at a high voltage.

A semiconductor device and a manufacturing method thereof are provided. The semiconductor device includes a substrate, a first well, a second well, and first and second doped regions. The substrate has heavily doped and lightly doped regions. The lightly doped region is disposed over the heavily doped region. The first well is disposed in the lightly doped region. The first well has a conductive type complementary to a conductive type of the heavily doped and lightly doped regions. The second well is disposed in the substrate over the lightly doped region. A location of the first well overlaps a location of the second well. The first and the second doped regions are located in the second well within the active region, and spaced apart from each other. The first and the second doped regions have a same conductive type complementary to a conductive type of the second well.

A method is presented for forming a monolithically integrated semiconductor device. The method includes forming a first device including first hydrogenated silicon-based contacts formed on a first portion of a semiconductor material of an insulating substrate and forming a second device including second hydrogenated silicon-based contacts formed on a second portion of the semiconductor material of the insulating substrate. Source and drain contacts of the first device are formed before a gate contact of the first device and a gate contact of the second device is formed before the emitter and collector contacts of the second device. The first device can be a heterojunction field effect transistor (HJFET) and the second device can be a (heterojunction bipolar transistor) HBT. The HJFET and the HBT are integrated in a neuronal circuit and create negative differential resistance by forming a lambda diode.

An electronic device includes a substrate having a second conductivity type including a semiconductor surface layer with a buried layer (BL) having a first conductivity type. In the semiconductor surface layer is a first doped region (e.g., collector) and a second doped region (e.g., emitter) both having the first conductivity type, with a third doped region (e.g., a base) having the second conductivity type within the second doped region, wherein the first doped region extends below and lateral to the third doped region. At least one row of deep trench (DT) isolation islands are within the first doped region each including a dielectric liner extending along a trench sidewall from the semiconductor surface layer to the BL with an associated deep doped region extending from the semiconductor surface layer to the BL. The deep doped regions can merge forming a merged deep doped region that spans the DT islands.

A bipolar transistor includes a collector. The collector is produced by a process wherein a first substantially homogeneously doped layer is formed at the bottom of a cavity. A second gradually doped layer is then formed by diffusion of dopants of the first substantially homogeneously doped layer.

In one embodiment, a TVS semiconductor device includes a P-N diode that is connected in parallel with a bipolar transistor wherein a breakdown voltage of the bipolar transistor is less than a breakdown voltage of the P-N diode.

The present invention discloses a self-aligned register structure for base polysilicon and a preparation method thereof. The self-aligned register structure comprises a silicon substrate having a partially oxidized region of SiO2 medium, a SiO2 medium protective layer is arranged at a center above the silicon substrate, base polysilicon layers are located at left and right sides of the SiO2 medium protective layer, the adjacent base polysilicon layers are symmetrical to the SiO2 medium protective layer at equal spacing, and the spacing is equal to a thickness of the base polysilicon layer. The self-aligned register structure for base polysilicon of the present invention meets an extremely high register requirement, guarantees the uniformity of electric parameters of devices, and eliminates physical or chemical damage to an intrinsic region when etching a surface of the silicon substrate during the forming of the base polysilicon, thus reducing the capacitance and enhancing the product yield; and meanwhile, the preparation method is simple, convenient, low in cost, and short in time.

In one embodiment, a TVS semiconductor device includes a P-N diode that is connected in parallel with a bipolar transistor wherein a breakdown voltage of the bipolar transistor is less than a breakdown voltage of the P-N diode.

A method of making a semiconductor device includes forming a first polysilicon structure over a first portion of a substrate. The method further includes forming a first spacer on a sidewall of the first polysilicon structure, wherein the first spacer has a concave corner region between an upper portion and a lower portion. The method further includes forming a protective layer covering an entirety of the first spacer and the first polysilicon structure, wherein the protective layer has a first thickness over the concave corner region and a second thickness over the first polysilicon structure, and a difference between the first thickness and the second thickness is at most 10% of the second thickness.