Abstract: Methods of self-aligned multiple patterning. A hardmask is deposited over an interlayer dielectric layer. A mandrel is formed over the hardmask. A block mask is formed that covers a first lengthwise section of the mandrel and that exposes second and third lengthwise sections of the mandrel. After forming the block mask, the second and third lengthwise sections of the mandrel are removed to define a pattern including respective first and second mandrel lines that are separated from each other by the first lengthwise section of the mandrel. The first mandrel line and the second mandrel line expose respective portions of the hardmask, and the first lengthwise section of the mandrel line covers another portion of the hardmask. The pattern is transferred to the hardmask with an etching process, and subsequently transferred to the interlayer dielectric layer with another etching process.

Abstract: Methods of self-aligned multiple patterning. First and second mandrels are formed over a hardmask, and a conformal spacer layer is deposited over the first mandrel, the second mandrel, and the hardmask between the first mandrel and the second mandrel. A planarizing layer is patterned to form first and second trenches that expose first and second lengthwise portions of the conformal spacer layer respectively between the first and second mandrels. After patterning the planarizing layer, the first and second lengthwise portions of the conformal spacer layer are removed with an etching process to expose respective portions of the hardmask along a non-mandrel line. A third lengthwise portion of the conformal spacer layer is masked during the etching process by a portion of the planarizing layer and defines a non-mandrel etch mask.

Abstract: Methods of self-aligned multiple patterning. A mandrel is formed over a hardmask, and a planarizing layer is formed over the mandrel and the hardmask. The planarizing layer is patterned to form first and second trenches exposing respective first and second lengthwise sections of the mandrel. A portion of the patterned planarizing layer covers a third lengthwise section of the mandrel arranged between the first and second lengthwise sections of the mandrel. After patterning the planarizing layer, the first and second lengthwise sections of the mandrel are removed with an etching process to define a pattern including a mandrel line exposing respective first portions of the hardmask. The third lengthwise section of the mandrel is masked by the portion of the planarizing layer during the etching process, and the third lengthwise section covers a second portion of the hardmask arranged along the mandrel line between the first portions of the hardmask.

Abstract: Methods of self-aligned multiple patterning. A mandrel is formed over a hardmask, and a planarizing layer is formed over the mandrel and the hardmask. The planarizing layer is patterned to form first and second trenches exposing respective first and second lengthwise sections of the mandrel. A portion of the patterned planarizing layer covers a third lengthwise section of the mandrel arranged between the first and second lengthwise sections of the mandrel. After patterning the planarizing layer, the first and second lengthwise sections of the mandrel are removed with an etching process to define a pattern including a mandrel line exposing respective first portions of the hardmask. The third lengthwise section of the mandrel is masked by the portion of the planarizing layer during the etching process, and the third lengthwise section covers a second portion of the hardmask arranged along the mandrel line between the first portions of the hardmask.

Abstract: Methods of self-aligned multiple patterning. A hardmask is deposited over an interlayer dielectric layer. A mandrel is formed over the hardmask. A block mask is formed that covers a first lengthwise section of the mandrel and that exposes second and third lengthwise sections of the mandrel. After forming the block mask, the second and third lengthwise sections of the mandrel are removed to define a pattern including respective first and second mandrel lines that are separated from each other by the first lengthwise section of the mandrel. The first mandrel line and the second mandrel line expose respective portions of the hardmask, and the first lengthwise section of the mandrel line covers another portion of the hardmask. The pattern is transferred to the hardmask with an etching process, and subsequently transferred to the interlayer dielectric layer with another etching process.

Abstract: Methods of self-aligned multiple patterning. First and second mandrels are formed over a hardmask, and a conformal spacer layer is deposited over the first mandrel, the second mandrel, and the hardmask between the first mandrel and the second mandrel. A planarizing layer is patterned to form first and second trenches that expose first and second lengthwise portions of the conformal spacer layer respectively between the first and second mandrels. After patterning the planarizing layer, the first and second lengthwise portions of the conformal spacer layer are removed with an etching process to expose respective portions of the hardmask along a non-mandrel line. A third lengthwise portion of the conformal spacer layer is masked during the etching process by a portion of the planarizing layer and defines a non-mandrel etch mask.

Abstract: Methods of forming an interconnect of an IC are disclosed. The methods include forming a first interlayer dielectric (ILD) layer and a second ILD layer with an ILD etch stop layer (ESL) therebetween. The ILD ESL has an etch rate that is at least five times slower than the first and second ILD layers, and may include, for example, aluminum oxynitride. A dual damascene (DD) hard mask is used to form a wire trench opening in the second ILD layer and a via opening in the first ILD layer, creating a via-wire opening. Due to the slower etch rate, the ILD ESL defines the via opening in the first ILD layer as a chamferless via opening. A unitary via-wire conductive structure coupled to the conductive structure in the via-wire opening can be formed from the via-wire opening.

Abstract: Methods of forming an interconnect of an IC are disclosed. The methods include forming a first interlayer dielectric (ILD) layer and a second ILD layer with an ILD etch stop layer (ESL) therebetween. The ILD ESL has an etch rate that is at least five times slower than the first and second ILD layers, and may include, for example, aluminum oxynitride. A dual damascene (DD) hard mask is used to form a wire trench opening in the second ILD layer and a via opening in the first ILD layer, creating a via-wire opening. Due to the slower etch rate, the ILD ESL defines the via opening in the first ILD layer as a chamferless via opening. A unitary via-wire conductive structure coupled to the conductive structure in the via-wire opening can be formed from the via-wire opening.

Abstract: Methods of self-aligned double patterning and improved interconnect structures formed by self-aligned double patterning. A mandrel line including an upper layer and a lower layer is formed over a hardmask. A non-mandrel cut block is formed over a portion of a non-mandrel line, after which the upper layer of the mandrel line is removed. An etch mask is formed over a first section of the lower layer of the mandrel line defining a mandrel cut block over a first portion of the hardmask. The first section of the lower layer is arranged between adjacent second sections of the lower layer. The second sections of the lower layer of the mandrel line are removed to expose respective second portions of the hardmask, and the second portions of the hardmask are removed to form a trench. The mandrel cut block masks the first portion of the hardmask during the etching process.