United Microelectronics Corp.

Nan Ya Technology Corporation

Top Team/microelectronics Corp.

Jengping Lin

Sun-Chieh Chien

Han Lin

Chen-Chiu Hsue

Tzu-Ching Tsai

Lin-Chin Su

Tse Yao Huang

Chungwei Hsu

Ronfu Chu

Quentin Chen

A method for fabricating a self-aligned contact hole in accordance with the present invention is disclosed. First a conductive layer, a silicon oxide layer, and a first silicon nitride layer are formed on a silicon substrate. Next, the first silicon nitride layer, the silicon oxide layer, and the conductive layer are etched to form a trench. Then, a BPSG layer is formed over the first silicon nitride layer. A photoresist layer having an opening is defined. Then, using the photoresist layer as the masking layer, a part of BPSG layer is etched to form a self-aligned hole. Next, the photoresist layer is removed. Afterward, a second silicon nitride layer is formed and etched back to form a spacer.

Method for fabricating self-aligned contact hole

The present invention discloses a method of optical correction for improving the pattern shrinkage caused by scattering of the light during photolithography processes, wherein the patterns on photomasks are corrected by providing aid patterns. Therefore, serifs or hammerheads are not necessary, and the costs can be decreased. According to the present invention, a chrome aid block is provided between the edges of the patterns. It is noted that the size of the chrome aid block is between &frac13; to &frac12; the wavelength of light used during exposure. Therefore, the pattern shrinkage caused by scattering of the light during exposure can be reduced, and there is no additional block formed on the photoresist layer. In addition, the standing wave effect can be prevented; thus, the pattern transfer is more accurate.

Method of optical correction for improving the pattern shrinkage caused by scattering of the light

A method of a method of fabricating a contact. A substrate having a plurality of gates and a plurality of lightly doped source/drain regions is provided. A dielectric layer is formed and patterned to form a self-align contact window to expose a first lightly doped source/drain region of said lightly doped source/drain regions, and to form a first spacer on a side wall of a first gate of said gates simultaneously. An ion implantation is performed by using the first spacer as a mask, so that a first heavily doped source/drain region is formed in the first lightly doped source/drain region. A doped poly-silicon layer is formed over the substrate, and a metal silicide layer is formed on the doped poly-silicon layer. The doped poly-silicon and the metal silicide layer are patterned to form a self-align contact.

Method of fabricating self-aligned contact

The present invention relates to a method of manufacturing MOS components having lightly doped drains wherein the implanting type ion used is different than that used in the formation of the source/drain regions. The present invention also includes the use of a tilt implantation angle accompanied by substrate rotation during the implantation process to form lightly doped drain structures on two sides of the source/drain regions. The mask is the same for the formation of the source/drain regions as that for the formation of the lightly doped drain regions. The method of manufacturing MOS components having lightly doped drains according to this invention has fewer manufacturing processes for the formation of spacers than the conventional methods. Moreover, the reduction in spacer production results in an increased contact surface area for subsequent contact window formation, thereby lowering contact resistance.

Method of manufacturing MOS components having lightly doped drain

Device isolation is provided for a MOSFET circuit by providing channel stop regions comprising a distribution of dopants localized beneath and adjacent to corresponding field oxide regions. Channel stop regions are not formed under the channel regions of the MOSFETs and are selectively formed under the narrower field oxide regions which are most likely to provide inadequate device isolation. The channel stop regions are formed subsequent to the formation of field oxide regions, beginning by forming polysilicon spacers so that the polysilicon spacers extend over the bird's beak regions of the field oxide regions. Next, a channel stop mask having openings over selected field oxide regions is formed. Trenches are etched near the center of the exposed field oxide regions, leaving approximately 500 .ANG. of oxide on the bottom of the trench. Ions are implanted through the bottom of the trenches to form channel stop regions beneath the field oxide regions.

Method of forming MOSFET devices with heavily doped local channel stops

A method of forming WSi.sub.x sidewall spacers as an etching stop in the fabrication process of a buried contact. After a gate dielectric layer and a first conducting layer are formed over a substrate, an opening is formed by etching through the gate dielectric layer and first conducting layer. WSi.sub.x sidewall spacers are thereafter formed on the sidewalls of the opening. Then, a second conducting layer is deposited onto the overall surface as well as being connected to the substrate via the opening. When the second and first conducting layers are patterned and etched to form a gate electrode and an interconnect layer, the WSi.sub.x acts as the etching stop to prevent the formation of ditches in the substrate.

Method of fabricating a buried contact structure with WSi.sub.x sidewall

An improved FET device in which the hot carrier immunity and current driving capability are improved, and the subthreshold leakage current is minimized. The device has a gate electrode with vertical sidewalls, and a thin layer of SiO.sub.2 over the electrode. A first polysilicon spacer is provided on the vertical sidewalls, with a second overlying oxide spacer over the first spacer. The top portion of the SiO.sub.2 layer between the gate electrode and the polysilicon spacer is made conductive enough to keep the gate electrode and the polysilicon spacer at the same potential. Lightly doped source and drain regions are provided.

Method of fabricating FET device with double spacer

A process for manufacturing an LDD type of FET, based on the salicide process, is described. Said process does not lead to short circuits between the drain region and and the main body of the FET through the buried contact. The process is based on the use of Liquid Phase Deposition (LPD) as the method for growing the oxide layer from which the spacers are formed. Since oxide layers formed through LPD will deposit preferentially on silicon and silicon oxide surfaces relative to photoresist surfaces, the areas in which the LPD layer forms are readily controlled. This feature allows the buried contact layer to be replaced by an extended drain region which can be connected to other parts of the integrated circuit (by the salicide process) without the danger of shorting paths being formed therein.

Use of oxide spacers formed by liquid phase deposition

A method for fabricating a silicide shunt for use in dual-gate CMOS devices makes use of a nitrogen-containing silicide layer overlying the juncture between the P-type polysilicon layer and the N-type polysilicon layer. The nitrogen-containing silicide layer is formed by implanting nitrogen-containing ions, such as .sup.28 N.sub.2.sup.+, into a partial or overall silicide shunt which was originally deposited over the P-type polysilicon layer and N-type polysilicon layer. Therefore, the nitrogen-containing silicide layer can serve as a diffusion barrier layer retarding the lateral dopant diffusion of these polysilicon layers via the silicide shunt.

Method for fabricating silicide shunt of dual-gate CMOS device

Disclosed is a semiconductor fabrication process for fabricating MOS transistors in which ions are implanted only beneath the channel and are not overlapped with the source/drain regions so as to significantly reduce the junction capacitance of the source/drain regions for performance enhancement. The process comprises a first step of preparing a silicon substrate on which a field oxide region is formed to define an active region. In the second step, a phase-shift mask is used to define a substantially rectangular removal portion on a photoresist layer. One side of the rectangular removal portion is substantially aligned with the channel of the MOS transistor to be fabricated and the other three sides are placed within the field oxide region. In the third step, an anti-punchthrough implantation process is performed, in which ions are implanted through the removal portion of the photoresist layer to form an anti-punchthrough implant region beneath the channel of the MOS transistor; and in the final step, a gate region and source/drain regions are formed. The thus formed anti-punchthrough implant region is right beneath the channel of the MOS transistor and does not overlap with the source/drain regions. The packing density and performance of chips containing MOS transistors thus fabricated are high.

Process for fabricating MOS transistors having anti-punchthrough implant

This invention provides a method of fabricating a self-aligned contact of a semiconductor device using a liquid-phase oxide-deposition (LPD) process. A gate electrode and source/drain regions are formed on a semiconductor substrate. A layer of photoresist is coated and patterned overlying an area of the semiconductor substrate that will form a contact. Using the photoresist as a mask, an oxide layer is formed in self-aligned manner by a liquid-phase deposition process. The photoresist is removed to expose a contact portion of the source/drain regions. An interlevel conductive layer is formed on the semiconductor substrate, wherein the interlevel conductive layer is connected to the source/drain regions through the contact portion.

Method of fabricating a self-aligned contact using a liquid-phase

A method of fabricating an asymmetric lightly doped drain transistor device. The device's drain region is shielded with a barrier layer when ion implantation is applied to a implant a highly doped source region. A large angle implantation then follows to form a lightly doped pocket region adjacent to the highly doped source region. The implantation forming the pocket region increases the doping concentration along the device's source side which increases the device's threshold voltage diminishing short channel effects.

Method of fabricating an asymmetric lightly doped drain transistor device

A structure and method is provided for forming a contact plug in a contact hole in a dielectric layer on a semiconductor substrate. A polysilicon spacer is formed on the sidewalls and bottom of the contact hole. A metal, such as titanium, is deposited on the sidewalls and bottom of the hole and on the dielectric layer. The substrate is heated to form a metal silicide layer, such as TiSi.sub.x, and a metal nitride layer, such as TiN, on the side-walls and bottom of the contact hole. Any remaining metal layer and metal nitride layer formed in the heating process is removed. This leaves the titanium silicide layer on the contact hole walls. Tungsten is deposited to fill the contact hole where the metal silicide promotes the nucleation of the tungsten. In a preferred embodiment, to further promote nucleation of the tungsten, a second metal nitride layer is formed on the surface; of the metal silicide layer just prior to tungsten deposition.

Method for selective tungsten sidewall and bottom contact formation

A method for fabricating gate oxide layers of different thicknesses on a silicon substrate. A field oxide layer is formed on a predetermined portion of the silicon substrate to define first active regions and second active regions. A first gate oxide layer is formed over the first and second active regions. A barrier layer is formed to cover a portion of the first gate oxide layer within the first active regions. The portion of the first gate oxide layer within the second active regions is then removed utilizing the barrier layer as masking. A second gate oxide layer is then formed over the second active regions.

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Taoyuan Hsien, Taiwan

Jengping Lin