摘要:
A method of fabricating a recess channel transistor is provided. First, a hard mask is formed on a doped-semiconductor layer and a substrate. The doped-semiconductor layer and the substrate are etched to form a trench and define a source/drain in the doped-semiconductor layer. An implantation process is performed with a tilt angle on sidewalls of the trench to form an implant area. A thermal oxidation process is performed to form an oxide layer. The oxide layer comprises a first thickness on the source/drain in the sidewalls of the trench and a second thickness on the other portion in the sidewalls of the trench.
摘要:
A method of fabricating a field effect transistor, wherein a substrate with a gate is provided. A liner oxide layer and a first spacer are formed adjacent to the sides of the gate. An epitaxial silicon layer is formed at both sides of the gate in the substrate, while a shallow source/drain (S/D) extension junction is formed in the substrate below the epitaxial silicon layer. An oxide layer and a second spacer are formed to be closely connected to the first spacer and form the S/D region below the epitaxial silicon layer. A part of the epitaxial silicon layer is then transformed into a metal silicide layer, so as to complete the process of the field effect transistor.
摘要:
A method for forming a gate that improves the quality of the gate includes sequentially forming a gate oxide layer, a polysilicon layer, a conductive layer and a masking layer on a substrate. Thereafter, the masking layer, the conductive layer, the polysilicon layer and the gate oxide layer are patterned to form the gate. Then, a passivation layer, for increasing the thermal stability and the chemical stability of the gate, is formed on the sidewall of the conductive layer by ion implantation with nitrogen cations. The nitrogen cations are doped into the substrate, under the gate oxide layer, by ion implantation, which can improve the penetration of the phosphorus ions.
摘要:
A method for forming an amorphous silicon layer over the terminals of a MOS transistor. The method includes the steps of forming a mask layer having an opening that exposes the gate polysilicon layer over the MOS transistor. Next, using the mask layer as a mask, an inactive ion implant operation is carried out such that inactive ions are implanted into the gate polysilicon layer. Thereafter, again using the mask layer as a mask, a first heavy bombarding operation is carried out, implanting ions locally. Finally, the mask layer is removed and then a second heavy bombarding operation is carried out, implanting ions globally.
摘要:
A new improvement for selective epitaxial growth is disclosed. In one embodiment, the present invention provides a low power metal oxide semiconductor field effect transistor (MOSFET), which includes a substrate. Next, a gate oxide layer is formed on the substrate. Moreover, a polysilicon layer is deposited on the gate oxide layer. Patterning to etch the polysilicon layer and the gate oxide layer to define a gate. First ions are implanted into the substrate by using said gate as a hard mask. Sequentially, a liner oxide is covered over the entire exposed surface of the resulting structure. Moreover, a conformal first dielectric layer and second dielectric layer are deposited above the liner oxide in proper order. The second dielectric layer is etched back to form a dielectric spacer on sidewall of the first dielectric layer. Next, the first dielectric layer is etched until upper surface of the gate and a portion of the substrate are exposed, wherein a part of the second dielectric layer is also etched accompanying with etching a part of the first dielectric layer. Further, second ions are implanted into the exposed substrate to form a source/drain region. A conductive layer is selectively formed on said over the exposed gate and source/drain. Finally, a self-aligned silicide layer is formed over the conductive layer.
摘要:
A read-only memory (ROM) device of the type including an array of diode-based memory cells for permanent storage of binary-coded data. The ROM device is partitioned into a memory division and an output division. The memory cells are formed over an insulating layer in the memory division. The insulating layer separates the memory cells from the underlying substrate such that the leakage current that can otherwise occur therebetween can be prevented. Moreover, the coding process is performing by forming contact windows at selected locations rather than by performing ion-implantation as in conventional methods. The fabrication process is thus easy to perform. Since the memory cells are diode-based rather than MOSFET-based, the punch-through effect that usually occurs in MOSFET-based memory cells can be prevented. The diode-based structure also allows the packing density of the memory cells on the ROM device to be dependent on the line width of the polysilicon layers in the ROM device. The feature size of the ROM device is thus dependent on the capability of the photolithographic process. The integration of the ROM device is thus high. The output division includes a plurality of MOSFETs whose gates are coupled to the memory cells in such a manner that the binary data can be read out by detecting the currents in the source/drain regions of these MOSFETs.
摘要:
A method for forming shallow trench isolation comprising the steps of providing a substrate having a mask layer formed thereon. Next, the mask layer is patterned to form a first trench in the substrate. Then, dielectric spacers are formed on the sidewalls of the first trench. After that, a second trench is formed in the substrate by an etching operation following the profile of the dielectric spacers. Next, a second dielectric layer is formed filling the second trench, wherein the second dielectric layer and the dielectric spacers are formed from different materials. Thereafter, the dielectric spacers are removed to form recess cavities, and then a filler material is deposited into the recess cavities. Subsequently, a gate oxide layer is formed over the filler material and the substrate. Finally, a polysilicon gate layer is formed over the gate oxide layer.
摘要:
A method of fabricating a metal-oxide semiconductor (MOS) transistor is provided. This method is devised particularly to reduce the level of degradation to the MOS transistor caused by hot carriers. In the fabrication process, a plasma treatment is applied to the wafer to as to cause the forming of a thin layer of silicon nitride on the wafer which covers the gate and the lightly-doped diffusion (LDD) regions on the source/drain regions of the MOS transistor. This thin layer of silicon nitride acts as a barrier which prevents hot carriers from crossing the gate dielectric layer, such that the degradation of the MOS transistor due to hot carriers crossing the gate dielectric layer can be greatly minimized.
摘要:
A ROM device of the type including an array of diode-type memory cells and a method for fabricating the same are provided. The bit lines of this ROM device are a plurality of diffusion regions formed in an alternate manner on the bottom of a plurality of parallel-spaced trenches and on the top of the solid portions between these trenches. This particular arrangement of the bit lines allows for an increased integration of the diode-type memory cells on a limited wafer surface without having to reduce the feature size of the semiconductor components of the ROM device. The diode-type memory cells that are set to a permanently-ON state involve a P-N junction diode being formed therein, wherein the P-N junction diode is electrically connected via a contact window in an insulating layer to the associated one of the overlaying word lines. Other memory cells that are set to a permanently-OFF state are formed with no P-N junction diode therein.
摘要:
A dynamic random access memory (DRAM) is provided. The dynamic random access memory includes a deep trench capacitor disposed in a first trench of a substrate, a conductive layer disposed in a second trench of the substrate, a gate structure, and a conductive layer disposed on the surface of the substrate at two sides of the gate structure. The depth of the second trench is smaller than the depth of the first trench, and the second trench partially overlaps with the first trench. The conductive layer disposed in the second trench is electrically connected with the conductive layer of the deep trench capacitor. The gate structure is disposed on the substrate. The conductive layer at one side of the gate structure is electrically connected with the conductive layer disposed in the second trench.