United Microelectronics Corp.

Feng-Yih Chang

Chih-Wen Feng

Jiunn-Hsiung Liao

Chieh-Te Chen

Pei-Yu Chou

Ying-Chih Lin

Shang-Yuan Tsai

Yi-Po Lin

In an exemplary method for forming contact holes, a substrate overlaid with an etching stop layer and an interlayer dielectric layer in that order is firstly provided. A first etching process then is performed to form at least a first contact opening in the interlayer dielectric layer. A first carbon-containing dielectric layer subsequently is formed overlying the interlayer dielectric layer and filling into the first contact opening. After that, a first anti-reflective layer and a first patterned photo resist layer are sequentially formed in that order overlying the carbon-containing dielectric layer. Next, a second etching process is performed by using the first patterned photo resist layer as an etching mask to form at least a second contact opening in the interlayer dielectric layer.

Method for forming contact holes

A method for controlling an ADI-AEI CD difference ratio of openings having different sizes is described. The openings are formed through a silicon-containing material layer, an etching resistive layer and a target material layer in turn. Before the opening etching steps, at least one of the opening patterns in the photoresist mask is altered in size through photoresist trimming or deposition of a substantially conformal polymer layer. A first etching step forming thicker polymer on the sidewall of the wider opening pattern is performed to form a patterned Si-containing material layer. A second etching step is performed to remove exposed portions of the etching resistive layer and the target material layer. At least one parameter among the parameters of the photoresist trimming or polymer layer deposition step and the etching parameters of the first etching step is controlled to obtain a predetermined ADI-AEI CD difference ratio.

Method for controlling ADI-AEI CD difference ratio of openings having different sizes

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Tainan, Taiwan

Feng-Yih Chang