摘要:
A method for forming a metal silicide contact for a semiconductor device includes forming a refractory metal layer over a substrate, including active and non-active area of said substrate, and forming a cap layer over the refractory metal layer. A counter tensile layer is formed over the cap layer, wherein the counter tensile layer is selected from a material such that an opposing directional stress is created between the counter tensile layer and the cap layer, with respect to a directional stress created between the refractory metal layer and the cap layer.
摘要:
The present invention provides a method for enhancing uni-directional diffusion of a metal during silicidation by using a metal-containing silicon alloy in conjunction with a first anneal in which two distinct thermal cycles are performed. The first thermal cycle of the first anneal is performed at a temperature that is capable of enhancing the uni-directional diffusion of metal, e.g., Co and/or Ni, into a Si-containing layer. The first thermal cycle causes an amorphous metal-containing silicide to form. The second thermal cycle is performed at a temperature that converts the amorphous metal-containing silicide into a crystallized metal rich silicide that is substantially non-etchable as compared to the metal-containing silicon alloy layer or a pure metal-containing layer. Following the first anneal, a selective etch is performed to remove any unreacted metal-containing alloy layer from the structure. A second anneal is performed to convert the metal rich silicide phase formed by the two thermal cycles of the first anneal into a metal silicide phase that is in its lowest resistance phase. A metal silicide is provided whose thickness is self-limiting.
摘要:
A method of forming a salicide on a semiconductor device includes depositing a first refractory metal layer over a silicon region of a substrate, depositing a near-noble metal layer over the first refractory metal layer, and depositing a second refractory metal layer over the near-noble metal layer. The semiconductor device is annealed in a first annealing process to form a silicide layer abutting the doped region of the semiconductor device. Un-reacted portions of the near-noble metal layer and the second refractory metal layer are removed. The device may be annealed in an optional second annealing process to convert the silicide layer to a low resistance phase silicide material. Junction leakage and bridging are minimized or eliminated by embodiments of the present invention, and a smoother silicided surface is achieved.
摘要:
A method of forming a semiconductor device including forming a second deposit of silicon-germanium on a first deposit of silicon-germanium, the first deposit formed in a conduction terminal region of a substrate of the semiconductor device and having a first percentage of germanium, and the second deposit having a second percentage of germanium that is less than the first percentage and supports forming a silicide deposit on the second deposit. A structure is also provided.
摘要:
Disclosed is a method and structure for forming a silicide on a silicon material. The invention places the silicon material in a vacuum environment, forms metal on the silicon material, and then heats the silicon surface and the metal without breaking the vacuum environment. The processes of forming the metal and heating the silicon can be performed simultaneously without breaking the vacuum environment to form the silicide as the metal is being deposited. After the foregoing processing, the invention can remove the silicon surface from the vacuum environment and perform additional heating of the silicon surface. The first heating process forms a monosilicide and the additional heating forms a disilicide.
摘要:
A method for forming a metal suicide contact for a semiconductor device includes forming a refractory metal layer over a substrate, including active and non-active area of said substrate, and forming a cap layer over the refractory metal layer. A counter tensile layer is formed over the cap layer, wherein the counter tensile layer is selected from a material such that an opposing directional stress is created between the counter tensile layer and the cap layer, with respect to a directional stress created between the refractory metal layer and the cap layer.
摘要:
The present invention provides a method for forming an interconnect to a cobalt or nickel silicide having a TiN diffusion barrier. The inventive method comprises providing an initial structure having vias to exposed silicide regions positioned on a substrate; annealing the initial structure in a nitrogen-containing ambient, wherein a nitrogen passivation layer is formed atop the exposed silicide region; depositing Ti atop the nitrogen passivation layer; annealing the Ti in a nitrogen-containing ambient to form a TiN diffusion barrier and an amorphous Ti cobalt silicide between the TiN diffusion layer and the cobalt or nickel silicide and depositing an interconnect metal within the vias and atop the TiN diffusion barrier. The nitrogen passivation layer substantially restricts diffusion between the Ti and silicide layers minimizing the amorphous Ti cobalt silicide layer that forms. Therefore, the amorphous Ti cobalt or Ti nickel silicide is restricted to a thickness of less than about 3.0 nm.
摘要:
A method for forming a TiN layer on top of a metal silicide layer in a semiconductor structure without the formation of a thick amorphous layer containing Ti, Co and Si and the structure formed are provided. In the method, after a Ti layer is deposited on top of a metal silidide layer, a dual-step annealing process is conducted in which a low temperature annealing in a forming gas (or ammonia) at a temperature not higher than 500° C. is first conducted for less than 2 hours followed by a high temperature annealing in a nitrogen-containing gas (or ammonia) at a second temperature not lower than 500° for less than 2 hours to form the TiN layer. The present invention method prevents the problem usually caused by a thick amorphous material layer of Ti—Si—Co which produces weakly bonded Ti which reacts with fluorine atoms from WF6 during a subsequent CVD W deposition process and causes liner failure due to a volume expansion of the amorphous material. The maximum thickness of the amorphous material layer formed by the present invention method is less than 5 nm which minimizes the line failure problem.
摘要:
A method of reducing the contact resistance of metal silicides to the p+ silicon area or the n+ silicon area of the substrate comprising: (a) forming a metal germanium (Ge) layer over a silicon-containing substrate, wherein said metal is selected from the group consisting of Co, Ti, Ni and mixtures thereof; (b) optionally forming an oxygen barrier layer over said metal germanium layer; (c) annealing said metal germanium layer at a temperature which is effective in converting at least a portion thereof into a substantially non-etchable metal silicide layer, while forming a Si—Ge interlayer between said silicon-containing substrate and said substantially non-etchable metal silicide layer; and (d) removing said optional oxygen barrier layer and any remaining alloy layer. When a Co or Ti alloy is employed, e.g., Co—Ge or Ti—Ge, two annealing steps are required to provide the lowest resistance phase of those metals, whereas, when Ni is employed, a single annealing step forms the lowest resistance phase of Ni silicide.
摘要:
A method of producing electrical contacts having reduced interface roughness as well as the electrical contacts themselves are disclosed herein. The method of the present invention comprises (a) forming an alloy layer having the formula MX, wherein M is a metal selected from the group consisting of Co and Ni and X is an alloying additives over a silicon-containing substrate; (b) optionally forming an optional oxygen barrier layer over said alloy layer; (c) annealing said alloy layer at a temperature sufficient to form a MXSi layer in said structure; (d) removing said optional oxygen barrier layer and any remaining alloy layer; and optionally (e) annealing said MXSi layer at a temperature sufficient to form a MXSi2 layer in said structure.