United Microelectronics Corp.

Other

United Silicon Incorporated

Hsi-Mao Hsiao

Chun-Lung Chen

Hsi-Chin Lin

Wen-Hua Cheng

Wen-Shan Wei

H C Yu

Tzung-Han Lee

Chuan-Fu Wang

Tong-Hsin Lee

Chia-Fu Yeh

Ming-Sheng Kuo

Hung-Chen Yu

Jung-Huang Chen

Hong-Chen Yu

Shin-Fa Lin

A method is disclosed for forming the lower storage node and contact for capacitors on a semiconductor wafer. The method includes an etch back process to remove a portion of the silicon oxide layer around the mouth of the contact hole to produce a rounded shoulder where the walls of the contact hole meet the face of the silicon oxide layer. When a contact plug is formed during a subsequent deposition process, the rounded shoulder results in local enlargement of the contact plug as well as filleting of reentrant corners. The contact plug therefore sustains substantially reduced mechanical stress during subsequent wafer cleaning processes. This stress reduction results in a reduced rate of lower node collapse and increased production yield of finished product.

Method of forming a lower storage node of a capacitor for dynamic random access memory

A semiconductor wafer has a substrate, a first region in the substrate that is used for a logic circuit, and a second region in the substrate that is used for a memory cell. A first gate in the first region and a second gate in the second region are simultaneously formed on the substrate. The first gate and the second gate both include a gate dielectric layer, a polysilicon layer, a tungsten silicide layer and a cap layer, in ascending order. The cap layer and the tungsten silicide layer are then removed from the first gate. A spacer around each gate is then formed. This completes the second type MOS transistor in the memory cell of DRAM. A titanium silicide layer on the surface of the substrate adjacent to the first gate and on the surface of the polysilicon layer of the first gate is formed so as to complete the formation of the first type MOS transistor.

Method for forming different types of MOS transistors on a semiconductor wafer

A method of fabricating a semiconductor device is described in which an insulation layer is formed over the gate electrode and the substrate. This insulation layer is anisotropically etched away except for a portion surrounding the sidewall of the gate electrode to form a spacer. The tip of the spacer is at the same height as the upper surface of the liner layer and is lower than the upper surface of the gate electrode, therefore, resulting in an increase of the exposed area of the gate electrode surface.

Method of fabricating a semiconductive device

The invention describes a method for fabricating an inter-layer dielectric layer. In this method, a plurality of first polysilicon lines, a first inter-layer dielectric layer, and a plurality of second polysilicon lines are formed in sequence on the substrate. A second inter-layer dielectric layer is formed between the plurality of second polysilicon lines and entirely covers the plurality of second polysilicon lines. Afterwards, a spin-on glass layer is formed on the second inter-layer dielectric layer, and then, while using the upper surfaces of the second polysilicon lines as etch end points, the spin-on glass layer and the second inter-layer dielectric layer are etched back to entirely remove the spin-on glass layer and partially remove the second inter-layer dielectric layer over the second polysilicon lines. Subsequently, a cover layer is formed to cover the second polysilicon lines and the remainder of the inter-layer dielectric layer. Finally, an oxide layer is formed to cover the resulting structure.

Method for forming an inter-layer dielectric layer

A method of fabricating a MOS transistor. A substrate has a gate formed thereon and a LDD is formed in the substrate beside the gate. A spacer is formed on the sidewall of the gate. A sacrificial layer is formed over the substrate to cover the gate and the spacer. A portion of the sacrificial layer is removed to expose a portion of the spacer. The exposed spacer is removed, such that a portion of the gate sidewall is exposed. The sacrificial layer is removed. A source/drain region is then formed in the substrate beside the spacer.

Method of fabricating a MOS device using a sacrificial layer and spacer

A fabrication process for a polysilicon gate is described in which a silicon dioxide layer of various thicknesses is formed on the substrate and on the polysilicon gate with an overlying anti-reflection layer. The silicon dioxide layer is removed with enough silicon dioxide layer remaining to cover the sidewalls of the polysilicon gate and the silicon substrate before the removal of the anti-reflection layer. The sidewalls of the polysilicon gate and the silicon substrate are thus simultaneously protected during the removal of the anti-reflection layer.

Fabricating process for polysilicon gate

A fabrication method for a gate spacer. The method comprises provision of a substrate with a gate formed thereon, after which a SiN,spacer is formed on the gate sidewall. The substrate is then covered with a SiO,layer. A part of the SiO,layer is removed until the surface of the SiO,layer is lower than the top surface of the gate. A portion of the SiN,layer is removed to expose the top edge of the gate spacer and to increase the exposed area of the gate. The SiO,layer is consequently removed.

Fabrication method for gate spacer

A damascene process is described. An opening is formed in a dielectric layer. The opening is filled with a conductive plug. The conductive plug is etched back to substantially reduce the thickness of the conductive plug in the dielectric layer. A conformal top barrier layer is formed over the conductive plug.

Damascene process

A method is used to form a shallow trench isolation structure. According to the invention, prior to performing CMP on a HDPCVD oxide layer, a smoothing step is performed on the HDPCVD oxide layer to smooth the peak profile of the oxide layer to reduce the moment resulting from the CMP on the peak, and to prevent the later-formed shallow trench isolation structure from being pulled out. In addition, since the invention prevents the later-formed shallow trench isolation structure from being pulled out, the particles resulting from the oxide pulled out from the shallow trench are reduced. Thus, particle damage to the surface of the wafer is reduced.

Process for forming a shallow trench isolation structure

A method of fabricating a lower electrode of a capacitor. A sacrificial multilayer is formed on a semiconductor layer. The sacrificial multi-layer is a stack of alternating first and second sacrificial layers. A patterned first mask layer having a first opening above a conductive plug in the semiconductor substrate is formed on the sacrificial multi-layer. A planar spacer is formed on the sidewall of the first opening. A second mask layer is formed to fill the first opening. The planar spacer and the sacrificial multi-layer thereunder are anisotropically etched until the semiconductor substrate is exposed to form a second opening while using the first mask layer and second mask layer as a mask. The first sacrificial layers exposed by the second opening are isotropically etched to form a plurality of recesses. The second opening and the recesses are filled with a conductive material layer. Finally, the first mask layer, second mask layer, and sacrificial multi-layer are removed.

Growing community of inventors

Hsinchu, Taiwan

Hsi-Mao Hsiao