Chartered Semiconductor Manufacturing Ltd (corporation)

Yimin Wang

Shao-fu Sanford Chu

Kai Shao

Jian Xun Li

Yong Ju

A method for forming a CMOS transistor gate with a self-aligned. channel implant. A semiconductor structure having a first active area is provided. A first insulating layer is formed on the semiconductor structure, and a second insulating layer is formed on the first insulating layer. The second insulating layer is patterned using a poly reverse mask and an etch selective to the first insulating layer to form a first channel implant opening, and the poly reverse mask is removed. A first channel implant mask is formed exposing the first channel implant opening. Impurity ions are implanted through the first channel implant opening to form a first threshhold adjust region and a first anti-punchthrough region. A gate layer is formed over the semiconductor structure, and the first gate layer is planarized to form a gate electrode. The second insulating layer is removed, and lightly doped source and drain regions, sidewall spacers and source and drain regions can be formed adjacent the gate electrode.

Method for forming self-aligned channel implants using a gate poly reverse mask

A method for forming a CMOS transistor gate with a self-aligned channel implant. A semiconductor structure having a first active area is provided. A first insulating layer is formed on the semiconductor structure, and a second insulating layer is formed on the first insulating layer. The second insulating layer is patterned using a poly reverse mask and an etch selective to the first insulating layer to form a first channel implant opening, and the poly reverse mask is removed. A first channel implant mask is formed exposing the first channel implant opening. Impurity ions are implanted through the first channel implant opening to form a first threshold adjust region and a first anti-punchthrough region. A gate layer is formed over the semiconductor structure, and the first gate layer is planarized to form a gate electrode. The second insulating layer is removed, and lightly doped source and drain regions, sidewall spacers and source and drain regions can be formed adjacent the gate electrode.

A process for simultaneously forming a polysilicon gate structure, for a transfer gate transistor, and a polysilicon top plate, for a capacitor structure, on an underlying planar surface, has been developed. The process features the formation of a polysilicon bottom plate, for the capacitor structure, embedded in a first opening in composite insulator layer, and the formation of an active device region, for a transfer gate transistor structure, via the selective growth of an epitaxial silicon layer, in a second opening of the composite insulator layer, resulting in a planar top surface topography. The presence of this topography reduces the risk of residual polysilicon, present after patterning of the polysilicon gate structure, and of the capacitor, polysilicon top plate.

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Singapore, Singapore

Yimin Wang