A semiconductor structure including a substrate, a dielectric layer and a polysilicon layer is provided. The dielectric layer is disposed on the substrate. The polysilicon layer is disposed on the dielectric layer. A fluorine dopant concentration in the polysilicon layer presents Gaussian distributions from a top portion to a bottom portion of the polysilicon layer. Fluorine dopant peak concentrations of the Gaussian distributions are progressively decreased from the top portion to the bottom portion of the polysilicon layer.

The present invention improves the linearity characteristics of a transistor, namely the input/output intercept points (IIP3/OIP3) and intermodulation distortion (IM3), while maintaining a high transconductance and high electron velocity in the conducting channel. The present invention also improves the manufacturability, yield, and immunity to bias-point drift, of a linear transistor. In one embodiment, the present invention implements triple pulse doping or even higher pulse doping for immunity to process variation as well as low parasitic leakage. In an alternative embodiment, the present invention implements a bilinear V-shaped composition grading for engineering the I.sub.D-V.sub.GS curve for high OIP3. In another alternative embodiment, the present invention implements a quadratic or U-shaped composition grading for engineering the I.sub.D-V.sub.GS curve for high OIP3.

A field effect transistor (FET) includes a substrate, a back barrier disposed on the substrate, a channel disposed on the back barrier, a front barrier disposed on the channel, a source, and a drain, such that at least one of the front barrier and the back barrier includes an anti-barrier-conduction (ABC) spacer which reduces parasitic conduction on a path from the source to the drain through at least one of the front barrier and the back barrier, reduces ON-state leakage from the channel to gate or substrate of the FET via resonant tunneling, and reduces OFF-state leakage by presenting tall barriers to electrons as well as electron-holes. This results in a highly linear, low gate leakage, low parasitic conduction, and low noise operation of FET.

A method of growing a conductive Ga.sub.2O.sub.3-based crystal film by MBE includes producing a Ga vapor and a Si-containing vapor and supplying the vapors as molecular beams onto a surface of a Ga.sub.2O.sub.3-based crystal substrate so as to grow the Ga.sub.2O.sub.3-based crystal film. The Ga.sub.2O.sub.3-based crystal film includes a Si-containing Ga.sub.2O.sub.3-based single crystal film. The Si-containing vapor is produced by heating Si or a Si compound and Ga while allowing the Si or a Si compound to contact with the Ga.

Techniques and structures for controlling etch-back of a finFET fin are described. One or more layers may be deposited over the fin and etched. Etch-back of a planarization layer may be used to determine a self-limited etch height of one or more layers adjacent the fin and a self-limited etch height of the fin. Strain-inducing material may be formed at regions of the etched fin to induce strain in the channel of a finFET.

A HEMT device is provided. The HEMT device includes a substrate, a first epitaxial layer, a second epitaxial layer, an insulating layer, a gate, a source, and a drain. The first epitaxial layer is formed on the substrate. The second epitaxial layer is formed on the first epitaxial layer. The insulating layer is formed on the second epitaxial layer. The gate is formed in the insulating layer and extends into the second epitaxial layer. The source and the drain are formed in the insulating layer and extend into the second epitaxial layer, wherein the source and the drain are located on both sides of the gate.

According to one embodiment, an apparatus includes a bottom electrode layer positioned above a substrate in a film thickness direction, a source layer positioned above the bottom electrode layer in the film thickness direction, an impact ionization channel (i-channel) layer positioned above the source layer in the film thickness direction, a drain layer positioned above the i-channel layer in the film thickness direction, an upper electrode layer positioned above the drain layer in the film thickness direction that forms a stack that includes the bottom electrode layer, the source layer, the i-channel layer, the drain layer, and the upper electrode layer, and a gate layer positioned on sides of the i-channel layer along a plane perpendicular to the film thickness direction in an element width direction. The gate layer is positioned closer to the drain layer than the source layer. Other apparatuses are described in accordance with more embodiments.

According to one embodiment, an apparatus includes a bottom electrode layer positioned above a substrate in a film thickness direction, a source layer positioned above the bottom electrode layer in the film thickness direction, an impact ionization channel (i-channel) layer positioned above the source layer in the film thickness direction, a drain layer positioned above the i-channel layer in the film thickness direction, an upper electrode layer positioned above the drain layer in the film thickness direction that forms a stack that includes the bottom electrode layer, the source layer, the i-channel layer, the drain layer, and the upper electrode layer, and a gate layer positioned on sides of the i-channel layer along a plane perpendicular to the film thickness direction in an element width direction. The gate layer is positioned closer to the drain layer than the source layer. Other apparatuses are described in accordance with more embodiments.

A physical vapor deposition (e.g., sputter deposition) method for III-nitride tunnel junction devices uses metal-organic chemical vapor deposition (MOCVD) to grow one or more light-emitting or light-absorbing structures and electron cyclotron resonance (ECR) sputtering to grow one or more tunnel junctions. In another method, the surface of the p-type layer is treated before deposition of the tunnel junction on the p-type layer. In yet another method, the whole device (including tunnel junction) is grown using MOCVD and the p-type layers of the III-nitride material are reactivated by lateral diffusion of hydrogen through mesa sidewalls in the III-nitride material, with one or more lateral dimensions of the mesa that are less than or equal to about 200 m. A flip chip display device is also disclosed.

In a semiconductor device having a heterojunction type superjunction structure, a drain portion and a source portion are electrically connected to one of a two-dimensional electron gas layer and a two-dimensional hole gas layer, and a gate portion is prevented by an insulating region from directly contacting the one of the two-dimensional election gas layer and the two-dimensional hole gas layer.