Abstract:
The present invention provides a method of forming a PMOS transistor or an NMOS transistor on a semiconductor wafer. The semiconductor wafer comprises a silicon substrate and a gate positioned on a predetermined area of the silicon substrate. First, a protection layer of uniform thickness made of silicon nitride is formed on the semiconductor wafer to cover the surface of the gate. Then, a first ion implantation process is performed to form a first ion implantation layer with a first predetermined thickness on the silicon substrate around the gate. Then, an RCA cleaning process is performed to remove impurities on the semiconductor wafer. Next, a spacer is formed around the gate. Finally, a second ion implantation process is performed to form a second ion implantation layer with a second predetermined thickness on the silicon substrate around the gate. The second ion implantation layer is used as a source or drain (S/D) of the MOS transistor. The portion of the first ion implantation layer that is not covered by the second ion implantation layer is used as a lightly doped drain (LDD). The protection layer is used to protect the surface of the silicon substrate from being etched during the RCA cleaning process so as to prevent an increase of the electrical resistance of the LDD.
Abstract:
A method for forming a semiconductor device is disclosed. The method includes providing a semiconductor substrate, followed by forming a gate oxide layer and a conductive layer over the substrate. An anti-reflective coating is then formed on the conductive layer. After patterning to etch the anti-reflective coating and the conductive layer, a gate region is thus formed. A dielectric layer is formed over the gate region, and is then subjected to etching back, therefore forming an offset spacer on sidewall of the gate region while simultaneously removing surface oxide of the anti-reflective coating. Finally, anti-reflective coating is removed.
Abstract:
A method for manufacturing an OTEPROM is described. A tunneling oxide layer, a first conductive layer, a first patterned mask layer are formed on a substrate. A trench is formed in the substrate. An insulating layer is formed to fill the trench. A portion of the first conductive layer destined to form the floating gate is exposed and then a cap layer is formed thereon. The first patterned mask layer is removed and then a second conductive layer and a second patterned mask layer are formed over the substrate. A word line and a floating gate are formed using the second patterned mask layer and the cap layer as a mask. The second patterned mask layer is removed and then source/drain regions are formed in the substrate on both sides of the word line and the floating gate and between the word line and the floating gate.
Abstract:
A method of forming borderless contacts is provided. A substrate is provided. The substrate has at least a logic region and a memory region. A MOS transistor and a STI structure are formed on the logic region. The MOS transistor comprises a gate, a source/drain region and a cap insulating layer on the gate. An etching stop layer is formed on the substrate to cover the MSO transistor and the STI structure. A dielectric layer is formed in the etching stop layer. The dielectric layer, the etching stop layer and the cap insulating layer are partially removed to form a first opening according to the pattern of a first mask layer. The first opening exposes the gate. According to the pattern of a second mask layer, the dielectric layer and the etching stop layer are partially removed to form openings, which expose the source/drain region, in the dielectric layer.
Abstract:
A process for forming high temperature stable self-aligned silicide layer that not only establishes itself smoothly and uniformly despite the use of a high temperature in the siliciding reaction, but also can withstand other subsequent high temperature thermal processing operations and maintaining a stable metal silicide layer profile thereafter. Moreover, desired thickness and uniformity of the metal silicide layer can be obtained by suitably adjusting the amorphous implant parameters, while the use of a titanium nitride cap layer help to stabilize the metal silicide layer during high temperature formation and that a stable and uniform metal silicide layer profile can be ensured even if subsequent high temperature processing operations are performed.
Abstract:
A method for cleaning a silicon wafer. The method includes intentionally exposing the wafer into a volatile solvent with a polarity between about 2 and 4, whereby the wafer is cleaned by the solvent such that the formation of silicon recesses in source/drain extension regions on the silicon wafer can be prevented or avoided.
Abstract:
A method to fabricate a salicide layer is described. The method is performed by forming a metal layer on the polysilicon gate and source/drain region and by a chemical vapor deposition using TiCl.sub.4 as a source gas. The metal layer is in situ transformed into a silicide layer in the formation step of the metal layer.
Abstract:
A method of manufacturing a non-volatile memory is provided. A substrate is provided and then a number of stacked gate structures are formed on the substrate. Each of the stacked gate structures includes a tunneling dielectric layer, a floating gate, a first inter-gate dielectric layer, a control gate and a cap layer. A source region is formed in the substrate, and a second inter-gate dielectric layer is formed over the substrate. A number of polysilicon select gates are formed on one side of the stacked gate structures. The select gates connect the stacked gate structures together to form a memory cell column. A spacer is formed on each sidewall of the memory cell column. A drain region is formed in the substrate on one side of the memory cell column. A silicidation process is carried out to convert the polysilicon constituting the select gate into a silicide material.
Abstract:
A method for manufacturing an OTEPROM is described. A tunneling oxide layer, a first conductive layer, a first patterned mask layer are formed on a substrate. A trench is formed in the substrate. An insulating layer is formed to fill the trench. A portion of the first conductive layer destined to form the floating gate is exposed and then a cap layer is formed thereon. The first patterned mask layer is removed and then a second conductive layer and a second patterned mask layer are formed over the substrate. A word line and a floating gate are formed using the second patterned mask layer and the cap layer as a mask. The second patterned mask layer is removed and then source/drain regions are formed in the substrate on both sides of the word line and the floating gate and between the word line and the floating gate.
Abstract:
A method for forming MOSFET is disclosed. The method includes firstly providing a substrate, on which a gate without spacer is already formed. A first spacer is formed on sidewall of the gate, a lightly doped drain is subsequently formed in the substrate. Next, a second spacer is formed on the first spacer. Finally, a heavily doped drain is formed in the substrate. The present invention can enhance stability of resistance of the gate and reduce pollution of the machine. Therefore, quality and efficiency of the fabrication of MOSFET will be enhanced.