Provided is a method for manufacturing a semiconductor device that improves the reliability of the semiconductor device. An opening is formed in an insulating film formed over a semiconductor substrate. At that time, a mask layer for formation of the opening is formed over the insulating film. The insulating film is dry etched and then wet etched. The dry etching step is finished before the semiconductor substrate is exposed at the bottom of the opening, and the wet etching step is finished after the semiconductor substrate is exposed at the bottom of the opening.

A method of forming an IC includes providing a field dielectric in a portion of a semiconductor surface, a bipolar or Schottky diode (BSD) class device area, a CMOS transistor area, and a resistor area. A polysilicon layer is deposited to provide a polysilicon gate area for MOS transistors in the CMOS transistor area, over the BSD class device area, and over the field dielectric for providing a polysilicon resistor in the resistor area. A first mask pattern is formed on the polysilicon layer. Using the first mask pattern, first implanting (I.sub.1) of the polysilicon resistor providing a first projected range (R.sub.P1)<a thickness of the polysilicon layer and second implanting (I.sub.2) providing a second R.sub.P(R.sub.P2), where R.sub.P2>R.sub.P1. I.sub.2 provides a CMOS implant into the semiconductor surface layer in the CMOS transistor area and/or a BSD implant into the semiconductor surface layer in the BSD area.

In some aspects of the invention, an n-type field-stop layer can have a total impurity of such an extent that a depletion layer spreading in response to an application of a rated voltage stops inside the n-type field-stop layer together with the total impurity of an n.sup. type drift layer. Also, the n-type field-stop layer can have a concentration gradient such that the impurity concentration of the n-type field-stop layer decreases from a p.sup.+ type collector layer toward a p-type base layer, and the diffusion depth is 20 m or more. Furthermore, an n.sup.+ type buffer layer of which the peak impurity concentration can be higher than that of the n-type field-stop layer at 610.sup.15 cm.sup.3 or more, and one-tenth or less of the peak impurity concentration of the p.sup.+ type collector layer, can be included between the n-type field-stop layer and p.sup.+ type collector layer.

The surface of an interlayer insulating film formed over an emitter coupling portion and the surface of an emitter electrode formed over the interlayer insulating film are caused to have a gentle shape, in particular, at the end of the emitter coupling portion, by forming the emitter coupling portion over a main surface of a semiconductor substrate and integrally with trench gate electrodes in order to form a spacer over the sidewall of the emitter coupling portion. Thereby, stress is dispersed, not concentrated in an acute angle portion of the emitter coupling portion when an emitter wire is coupled to the emitter electrode (emitter pad), and hence occurrence of a crack can be suppressed. Further, by forming the spacer, the concavities and convexities to be formed in the surface of the emitter electrode can be reduced, whereby the adhesiveness between the emitter electrode and the emitter wire can be improved.

An integrated circuit includes an NMOS transistor, a PMOS transistor and a vertical bipolar transistor. The vertical bipolar transistor has an intrinsic base with a band barrier at least 25 meV high at a surface boundary of the intrinsic base, except at an emitter-base junction with an emitter, and except at a base-collector junction with a collector. The intrinsic base may be laterally surrounded by an extrinsic base with a higher dopant density than the intrinsic base, wherein a higher dopant density provides the band barrier at lateral surfaces of the intrinsic base. A gate may be disposed on a gate dielectric layer over a top surface boundary of the intrinsic base adjacent to the emitter. The gate is configured to accumulate the intrinsic base immediately under the gate dielectric layer, providing the band barrier at the top surface boundary of the intrinsic base.

A method is provided of forming a bipolar transistor device. The method comprises depositing a collector dielectric layer over a substrate in a collector active region, depositing a dielectric anti-reflective (DARC) layer over the collector dielectric layer, dry etching away a base opening in the DARC layer, and wet etching away a portion of the collector dielectric layer in the base opening to provide an extended base opening to the substrate. The method further comprises performing a base deposition to form a base epitaxy region in the extended base opening and extending over first and second portions of the DARC layer that remains as a result of the dry etching away the base opening in the DARC layer, and forming an emitter region over the base epitaxy region.

Bipolar junction transistors including inorganic channels and organic emitter junctions are used in some applications for forming high resolution active matrix displays. Arrays of such bipolar junction transistors are electrically connected to thin film switching transistors and provide high drive currents for passive devices such as organic light emitting diodes.

A semiconductor device and manufacturing method achieve miniaturization, prevent rise in threshold voltage and on-state voltage, and prevent decrease in breakdown resistance. N.sup.+-type emitter region and p.sup.++-type contact region are repeatedly alternately disposed in a first direction in which a trench extends in stripe form in a mesa portion sandwiched between trench gates. P.sup.+-type region covers an end portion on lower side of junction interface between n.sup.+-type emitter region and p.sup.++-type contact region. Formation of trench gate structure is such that n.sup.+-type emitter region is selectively formed at predetermined intervals in the first direction in the mesa portion by first ion implantation. P.sup.+-type region is formed less deeply than n.sup.+-type emitter region in the entire mesa portion by second ion implantation. The p.sup.++-type contact region is selectively formed inside the p+-type region by third ion implantation. N.sup.+-type emitter region and p.sup.++-type contact region are diffused and brought into contact.

Methods of maintaining a state of a memory cell without interrupting access to the memory cell are provided, including applying a back bias to the cell to offset charge leakage out of a floating body of the cell, wherein a charge level of the floating body indicates a state of the memory cell; and accessing the cell.

Aspects of the present disclosure provides a device comprising a P-type semiconductor substrate, an N-type tub above the semiconductor substrate, a P-type region provided in the N-type tub isolated by one or more P-type isolation structures, and an N-type punch-through stopper provided under the P-type regions isolated by the isolation structure(s). The punch-through stopper is heavily doped compared to the N-type tub. The P-type region has a width between the two isolation structures that is equal to or less than that of the N-type punch-through stopper.