Techniques are disclosed for forming transistor devices having source and drain regions with high concentrations of boron doped germanium. In some embodiments, an in situ boron doped germanium, or alternatively, boron doped silicon germanium capped with a heavily boron doped germanium layer, are provided using selective epitaxial deposition in the source and drain regions and their corresponding tip regions. In some such cases, germanium concentration can be, for example, in excess of 50 atomic % and up to 100 atomic %, and the boron concentration can be, for instance, in excess of 1E20 cm.sup.3. A buffer providing graded germanium and/or boron concentrations can be used to better interface disparate layers. The concentration of boron doped in the germanium at the epi-metal interface effectively lowers parasitic resistance without degrading tip abruptness. The techniques can be embodied, for instance, in planar or non-planar transistor devices.

In a semiconductor device, a lightly doped second semiconductor layer of a first conductive type is joined with a heavily doped first semiconductor layer of the first conductive type. A power transistor having a first conductive type channel and a transistor are formed in surface regions of the second semiconductor layer, respectively. A first diffusion layer of a second conductive type is formed in a surface region of the second semiconductor layer to provide a boundary between the power transistor and the transistor. The first semiconductor layer functions as a drain of the power transistor. The first diffusion layer region is set to the same voltage as that of the drain.

A semiconductor device includes a first semiconductor region of a first conductivity type, a first electrode, a second electrode, a third electrode, a first insulation region, a second insulation region, a second semiconductor region of a second conductivity type, a third semiconductor region of the first conductivity type, a fourth semiconductor region of the second conductivity type, and a fourth electrode. The second electrode includes first portions and a second portion. The second portion extends in a first direction. The first portions extend in a direction away from the second portion. The second portion is between the first portions and the first electrode in a second direction. The fourth semiconductor region is positioned between adjacent first electrode portions in the first direction.

A semiconductor device is provided. The device includes a substrate having a first conductivity type. The device further includes a drain region, a source region, and a well region disposed in the substrate. The well region is disposed between the drain region and the source region and having a second conductivity type opposite to the first conductivity type. The device further includes a plurality of doped regions disposed within the well region. The doped regions are vertically and horizontally offset from each other. Each of the doped regions includes a lower portion having the first conductivity type, and an upper portion stacked on the lower region and having the second conductivity type.

The present invention provides a high voltage transistor including a substrate, a first base region having a first conductivity type, and a first doped region, a second doped region, a second base region and a third doped region having a second conductivity type complementary to the first conductivity type. The first base region, the second doped region, the second base region and the third doped region are disposed in the substrate, and the first doped region is disposed in the substrate. The third doped region, the second base region and the second doped region are stacked sequentially, and the doping concentrations of the third doped region, the second base region and the second doped region gradually increase.

A semiconductor device is provided. The device may include a semiconductor layer; and a doped well disposed in the semiconductor layer and having a first conductivity type. The device may also include a drain region, a source region, and a body region, where the source and body regions may operate in different voltages. Further, the device may include a first doped region having a second conductivity type, the first doped region disposed between the source region and the doped well; and a second doped region having the first conductivity type and disposed under the source region. The device may include a third doped region having the second conductivity type and disposed in the doped well; and a fourth doped region disposed above the third doped region, the fourth doped region having the first conductivity type. Additionally, the device may include a gate and a field plate.

A method of forming an integrated DMOS transistor/EEPROM cell includes forming a first mask over a substrate, forming a drift implant in the substrate using the first mask to align the drift implant, simultaneously forming a first floating gate over the drift implant, and a second floating gate spaced apart from the drift implant, forming a second mask covering the second floating gate and covering a portion of the first floating gate, forming a base implant in the substrate using an edge of the first floating gate to self-align the base implant region, and simultaneously forming a first control gate over the first floating gate and a second control gate over the second floating gate. The first floating gate, first control gate, drift implant, and base implant form components of the DMOS transistor, and the second floating gate and second control gate form components of the EEPROM cell.

A semiconductor device according to an embodiment includes a SiC layer having a first plane and a second plane, a gate insulating film provided on the first plane, a gate electrode provided on the gate insulating film, a first SiC region of a first conductivity type provided in the SiC layer, a second SiC region of a second conductivity type provided in the first SiC region, a third SiC region of the first conductivity type provided in the second SiC region, and a fourth SiC region of the first conductivity type provided between the second SiC region and the gate insulating film, the fourth SiC region interposed between the second SiC regions, and the fourth SiC region provided between the first SiC region and the third SiC region.

A semiconductor device includes a SiC layer having a first surface, a gate insulating film on the first surface, a gate electrode on the gate insulating film, a first SiC region of a first conductivity type in the SiC layer, a second SiC region of a second conductivity type in the first SiC region, a third SiC region of the first conductivity type in the second SiC region, wherein a boundary between the second SiC region and the third SiC region, and the first surface forms a first angle, and a fourth SiC region of the first conductivity type in the third SiC region, having an impurity concentration of the first conductivity type higher than that of the third SiC region, wherein a boundary between the third SiC region and the fourth SiC region, and the first surface forms a second angle that is smaller than the first angle.

A semiconductor device includes a superjunction structure formed using simultaneous N and P angled implants into the sidewall of a trench. The simultaneous N and P angled implants use different implant energies and dopants of different diffusion rate so that after annealing, alternating N and P thin semiconductor regions are formed. The alternating N and P thin semiconductor regions form a superjunction structure where a balanced space charge region is formed to enhance the breakdown voltage characteristic of the semiconductor device.