A bipolar junction transistor includes a collector having a first surface on a first level and a second surface on a second level. A base is formed on the second level of the collector, and an emitter is formed on the base. A dielectric liner is formed on vertical sidewalls of the collector, the base and the emitter and over the first surface. A conductive region is formed adjacent to the base in the dielectric liner. A base contact is formed along one of the vertical sidewalls to connect to the base through the conductive region.

A bipolar junction transistor includes a collector having a first surface on a first level and a second surface on a second level. A base is formed on the second level of the collector, and an emitter is formed on the base. A dielectric liner is formed on vertical sidewalls of the collector, the base and the emitter and over the first surface. A conductive region is formed adjacent to the base in the dielectric liner. A base contact is formed along one of the vertical sidewalls to connect to the base through the conductive region.

A method for producing a semiconductor memory device includes forming two Si pillars on a substrate. In the Si pillars, inverter circuits are formed. The inverter circuits include drive N-channel SGTs each including first and second N.sup.+ layers functioning as a source and a drain, and load SGTs each including first and second P.sup.+ layers functioning as a source and drain. Selection SGTs each including third and fourth N.sup.+ layers functioning as a source and a drain are formed above SiO.sub.2 layers disposed above the inverter circuits. The first N.sup.+ layer is connected to a ground wiring metal layer. The first P.sup.+ layers are connected to a power supply wiring metal layer through a NiSi layer. Gate TiN layers are connected to a word-line wiring metal layer through a NiSi layer. The third N.sup.+ layers are connected to an inverted bit-line wiring metal layer and a bit-line wiring metal layer.

A bipolar junction transistor includes a collector having a first surface on a first level and a second surface on a second level. A base is formed on the second level of the collector, and an emitter is formed on the base. A dielectric liner is formed on vertical sidewalls of the collector, the base and the emitter and over the first surface. A conductive region is formed adjacent to the base in the dielectric liner. A base contact is formed along one of the vertical sidewalls to connect to the base through the conductive region.

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.

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.

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.

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.

A method for producing a semiconductor memory device includes forming two Si pillars on a substrate. In the Si pillars, inverter circuits are formed. The inverter circuits include drive N-channel SGTs each including first and second N.sup.+ layers functioning as a source and a drain, and load SGTs each including first and second P.sup.+ layers functioning as a source and drain. Selection SGTs each including third and fourth N.sup.+ layers functioning as a source and a drain are formed above SiO.sub.2 layers disposed above the inverter circuits. The first N.sup.+ layer is connected to a ground wiring metal layer. The first P.sup.+ layers are connected to a power supply wiring metal layer through a NiSi layer. Gate TiN layers are connected to a word-line wiring metal layer through a NiSi layer. The third N.sup.+ layers are connected to an inverted bit-line wiring metal layer and a bit-line wiring metal layer.

A bipolar junction transistor includes a collector having a first surface on a first level and a second surface on a second level. A base is formed on the second level of the collector, and an emitter is formed on the base. A dielectric liner is formed on vertical sidewalls of the collector, the base and the emitter and over the first surface. A conductive region is formed adjacent to the base in the dielectric liner. A base contact is formed along one of the vertical sidewalls to connect to the base through the conductive region.