摘要:
Strained channel field effect transistors may have a threshold voltage shift. This threshold voltage shift may be compensated for by adjusting channel doping. But this also adversely affects mobility. The threshold voltage shift may be compensated, without adversely affecting mobility, by tailoring the workfunction of a metal gate electrode used in the transistor to adequately compensate for that threshold voltage shift. For example, in some embodiments, an appropriate metal may be selected with a slightly higher workfunction or, in other cases, the workfunction of a selected metal may be adjusted by, for example, doping the metal gate electrode with a material which increases the workfunction of the gate electrode.
摘要:
A semiconductor device comprising a gate electrode formed on a gate dielectric layer formed on a semiconductor film. A pair of source/drain regions are formed adjacent the channel region on opposite sides of the gate electrode. The source and drain regions each comprise a semiconductor portion adjacent to and in contact with the semiconductor channel and a metal portion adjacent to and in contact with the semiconductor portion.
摘要:
A method for making a semiconductor device is described. That method comprises forming a high-k gate dielectric layer that contacts a metal oxide layer. The metal oxide layer is generated by forming a metal layer, then oxidizing the metal layer.
摘要:
A method for making a semiconductor device is described. That method comprises adding nitrogen to a silicon dioxide layer to form a nitrided silicon dioxide layer on a substrate. After forming a sacrificial layer on the nitrided silicon dioxide layer, the sacrificial layer is removed to generate a trench. A high-k gate dielectric layer is formed on the nitrided silicon dioxide layer within the trench, and a metal gate electrode is formed on the high-k gate dielectric layer.
摘要:
A method for making a titanium carbide layer is described. That method comprises alternately introducing a carbon containing precursor and a titanium containing precursor into a chemical vapor deposition reactor, while a substrate is maintained at a selected temperature. The reactor is operated for a sufficient time, and pulse times are selected for the carbon containing precursor and the titanium containing precursor, to form a titanium carbide layer of a desired thickness and workfunction on the substrate.
摘要:
In a metal gate replacement process, strain may be selectively induced in the channels of NMOS and PMOS transistors. For example, a material having a higher coefficient of thermal expansion than the substrate may be used to form the gate electrodes of PMOS transistors. A material with a lower coefficient of thermal expansion than that of the substrate may be used to form the gate electrodes of NMOS transistors.
摘要:
Gate dielectrics formed of silicates of hafnium or zirconium dioxide may be formed by atomic layer deposition. The precursors for the atomic layer deposition may include an oxidant, a silicate precursor, and a zirconium or hafnium precursor.
摘要:
A method for making a semiconductor device is described. That method comprises forming a first dielectric layer on a substrate, a trench within the first dielectric layer, and a second dielectric layer on the substrate. The second dielectric layer has a first part that is formed in the trench and a second part. After a first metal layer with a first workfunction is formed on the first and second parts of the second dielectric layer, part of the first metal layer is converted into a second metal layer with a second workfunction.
摘要:
Replacement metal gates may be formed by removing a polysilicon layer from a gate structure. The gate structure may be formed by patterning the polysilicon layer and depositing a spacer layer over the gate structure such that the spacer layer has a first polish rate. The spacer layer is then etched to form a sidewall spacer. An interlayer dielectric is applied over the gate structure with the sidewall spacer. The interlayer dielectric has a second polish rate higher than the first polish rate. In one embodiment, the interlayer dielectric has a lower polish rate than that of oxide.
摘要:
In a metal gate replacement process, a stack of at least two polysilicon layers or other materials may be formed. Sidewall spacers may be formed on the stack. The stack may then be planarized. Next, the upper layer of the stack may be selectively removed. Then, the exposed portions of the sidewall spacers may be selectively removed. Finally, the lower portion of the stack may be removed to form a T-shaped trench which may be filled with the metal replacement.