If an optical path length of an optical system is reduced and a length of a laser light on an irradiation surface is increased, there occurs curvature of field which is a phenomenon that a convergent position deviates depending on an incident angle or incident position of a laser light with respect to a lens. To avoid this phenomenon, an optical element having a negative power such as a concave lens or a concave cylindrical lens is inserted to regulate the optical path length of the laser light and a convergent position is made coincident with a irradiation surface to form an image on the irradiation surface.

An insulated gate turn-off (IGTO) device, formed as a die, has a layered structure including a p+ layer (e.g., a substrate), an n epi layer, a p-well, trenched insulated gate regions formed in the p-well, and n+ regions between the gate regions, so that vertical NPN and PNP transistors are formed. The device may be formed of a matrix of cells or may be interdigitated. To turn the device on, a positive voltage is applied to the gate, referenced to the cathode. The cells further contain a vertical p-channel MOSFET, for rapidly turning the device off. The p-channel MOSFET may be made a depletion mode device by implanting boron ions at an angle into the trenches to create a p-channel. This allows the IGTO device to be turned off with a zero gate voltage while in a latch-up condition, when the device is acting like a thyristor.

The structures and methods disclosed herein include changing composition of a metal alloy layer in an epitaxial electrode material to achieve tunable work functions for the electrode. In one example, the tunable work function is achieved using a layered structure, in which a crystalline rare earth oxide (REO) layer is epitaxially over a substrate or semiconductor, and a metal layer is over the crystalline REO layer. A semiconductor layer is thus in turn epitaxially grown over the metal layer, with a metal alloy layer over the semiconductor layer such that the ratio of constituents in the metal alloy is used to tune the work function of the metal layer.

The reliability of a semiconductor device is improved. A first insulating film and a protective film are formed on a semiconductor substrate. The first insulating film and the protective film of a first region are selectively removed, and an insulating film is formed on the exposed semiconductor substrate. In a state where the first insulating film in a second region, a third region, and a fourth region is covered with the protective film, the semiconductor substrate is heat-treated in an atmosphere containing nitrogen, thereby introducing nitrogen to the interface between the semiconductor substrate and the second insulating film in the first region. In other words, a nitrogen introduction point is formed on the interface between the semiconductor substrate and the second insulating film. In this configuration, the protective film acts as an anti-nitriding film.

A semiconductor device includes a semiconductor part; first and second electrodes respectively on back and front surfaces of the semiconductor part; and a control electrode between the semiconductor part and the second electrode. The control electrode is provided inside a trench of the semiconductor part. The control electrode is electrically insulated from the semiconductor part by a first insulating film and electrically insulated from the second electrode by a second insulating film. The control electrode includes an insulator at a position apart from the first insulating film and the second insulating film. The semiconductor part includes a first layer of a first conductivity type provided between the first and second electrodes, the second layer of a second conductivity type provided between the first layer and the second electrode and the third layer of the first conductivity type selectively provided between the second layer and the second electrode.

Semiconductor devices, FinFET devices and methods of forming the same are disclosed. One of the semiconductor devices includes a substrate and a gate structure over the substrate. The gate structure includes a high-k layer over the substrate, a shielding layer over the high-k layer, and an N-type work function metal layer over the shielding layer. In some embodiments, the shielding layer has a dielectric constant less than a dielectric constant of the high-k layer.

A method of fabricating a replacement gate stack for a semiconductor device includes the following steps after removal of a dummy gate: growing a high-k dielectric layer over the area vacated by the dummy gate; depositing a thin metal layer over the high-k dielectric layer; depositing a sacrificial layer over the thin metal layer; performing a first rapid thermal anneal; removing the sacrificial layer; and depositing a metal layer of low resistivity metal for gap fill.

Methods for minimizing plasma-induced sidewall damage during low k etch processes are disclosed. The methods etch the low k layers using the plasma activated vapor of an organofluorine compound having a formula selected from the group consisting of NCR; (NC)(R)(CN); R.sub.x[CN(R.sub.z)].sub.y; and R.sub.(3-a)NH.sub.a, wherein a=1-2, x=1-2, y=1-2, z=0-1, x+z=1-3, and each R independently has the formula H.sub.aF.sub.bC.sub.c with a=0-11, b=0-11, and c=0-5.

A manufacturing method of an integrated circuit includes following steps. A dummy gate with a first mask structure formed thereon and a semiconductor gate with a second mask structure formed thereon are formed on a substrate. A top surface of the semiconductor gate is lower than a top surface of the dummy gate. A first removing process is performed to remove the first mask structure and a part of the second mask structure. A dielectric layer is formed covering the dummy gate, the semiconductor gate, and the second mask structure. A second removing process is performed to remove the dielectric layer above the dummy gate. The dummy gate is removed for forming a trench. A metal gate structure is formed in the trench. The semiconductor gate is covered by the second mask structure during the second removing process and the step of removing the dummy gate.

Semiconductor devices, FinFET devices and methods of forming the same are disclosed. One of the semiconductor devices includes a substrate and a gate structure over the substrate. The gate structure includes a high-k layer over the substrate, a shieling layer over the high-k layer, and an N-type work function metal layer over the shielding layer. In some embodiments, the shielding layer has a dielectric constant less than a dielectric constant of the high-k layer.