Abstract: To obtain a high mobility and a suitable threshold voltage in MOS transistors with channel dimensions in the deep sub-micron range, it is desirable to bury a strongly doped layer (or ground plane) in the channel region below a weakly doped intrinsic surface region, a few tens of nm below the surface. It was found, however, that degradation of the mobility can occur particularly in n-channel transistors owing to diffusion of boron atoms from the strongly doped layer to the surface, for example during the formation of the gate oxide. To prevent this degradation, a thin layer 11 of Si1−xGex inhibiting boron diffusion is provided between the strongly doped layer 10 and the intrinsic surface region 7, for example with x=0.3.

Abstract: A method of manufacturing a semiconductor device with a MOS transistor having an LDD structure. A gate dielectric (6) and a gate electrode (7, 8) are formed on a surface (5) of a silicon substrate (1). The surface adjacent the gate electrode is then exposed, and a layer of semiconductor material (10) is formed on an edge (9) of the surface adjoining the gate electrode. Ions (13, 14) are subsequently implated, with the gate electrode and the layer of semiconductor material acting as a mask. Finally, a heat treatment is carried out whereby a source zone (16, 17) and a drain zone (18, 19) are formed through activation of the implanted ions and through diffusion of atoms of a dopant from the layer of semiconductor material. The portions (b) of these zones formed by diffusion are weakly doped here and lie between the more strongly doped portions (a) formed through activation of implanted ions and the channel zone (20, 21). An LDD structure has thus been formed.

Abstract: In a method of manufacturing a semiconductor device comprising a field-effect transistor and a non-volatile memory element at a surface of a semiconductor body, a first and a second active region of a first conductivity type are defined at the surface of the semiconductor body for the transistor and the memory element, respectively. The surface of the semiconductor body is subsequently coated with a first insulating layer providing a sacrificial gate dielectric of the transistor and a floating gate dielectric of the memory element, which first insulating layer is then covered by a silicon-containing layer providing a sacrificial gate of the transistor and a floating gate of the memory element. After formation of the sacrificial gate and the floating gate, the transistor and the memory element are provided with source and drain zones of a second conductivity type.

Abstract: In a method of manufacturing a semiconductor device comprising a semiconductor body 1 which is provided at a surface 2 with a transistor comprising a gate structure 21, a patterned layer 10 is applied defining the area of the gate structure 21. Subsequently, a dielectric layer 18 is applied in such a way, that the thickness of the dielectric layer 18 next to the patterned layer 10 is substantially equally large or larger than the height of the patterned layer 10, which dielectric layer 18 is removed over part of its thickness until the patterned layer 10 is exposed. Then, the patterned layer 10 is subjected to a material removing treatment, thereby forming a recess 19 in the dielectric layer 18, and a contact window 28, 29 is provided in the dielectric layer.

Abstract: In the known replacement gate process, the relatively high-ohmic poly gate is replaced by a low-ohmic metal gate by depositing a thick oxide layer and subsequently planarizing this layer by CMP until the gate is reached, which gate can be selectively removed and replaced by a metal gate. The process is simplified considerably by providing the gate structure as a stack of a dummy poly gate (4) and a nitride layer (5) on top of the poly gate. When, during the CMP, the nitride layer is reached, the CMP is stopped, thereby precluding an attack on the poly. The nitride and the poly are selectively removed relative to the oxide layer (10).