Optimizing IC Interconnection: A Functional Approach to Innovation (Stay updated on the project's progress)

We need to create a Functional Model of IC Interconnection to understand and learn the functional and problem ranks of all components.

We will take one metal layer created above the layer below.

The purpose of the IC interconnection is to electrically connect the metal in the layer below to the metal line above. Therefore, the system's product would be Current.

The challenges are as follows:

We need a dielectric material (ILD) to be able to keep the metal line mechanically and separated electrically

ILD - Interlayer dielectric that is typically built of SiO2 or modified SiO2

The metal lines and via are made from Cu

Cu diffuses through the ILD, resulting in shortening - the creation of electrical contacts through ILD

The barrier (typically Ta) is used for preventing Cu diffusion into ILD within the layer

Etch stop layer (typically Si3N4, SiC) aims to prevent Cu diffusion to ILD on the upper layer

Cu is affected by the electromigration effect; therefore, the bottom Barrier that separates the top of the via from the metal at the low layer, helps to prevent the formation of huge voids due to Cu electromigration from layer to layer

The interconnection part is shown below:

Let's start to create a Functional Model.

The next step is to analyze the manufacturing process of the IC interconnection layer.

Generally, we need to process the structure:

To the structure:

Let's analyze all the steps needed to make an additional interconnection layer. We will use very general operations of the typical process used in many fabs for manufacturing BEOL layers.

Let's start, go to the "Model"

We need to complete 13 sequential operations to create a metal layer.

Generally speaking, two types of operations in semiconductor manufacturing aim to either deposit something or remove something.

A typical reasonable process flow is shown below:

Let's analyze the process using Process Functional Modeling, a creative thinking tool. No metrology operations were taken into account. Go to "Model"

1 Step is the transformation from the structure:

To the structure:

The Etch Stop layer is mainly needed to preserve the Cu diffusion to the ILD of the top layer - the top barrier. It is typically made of Si3N4 or SiC because increased density is needed to ensure barrier properties against Cu diffusion.

The Etch Stop layer deposition is usually performed by the CVD method.

The operation aims to create the Etch Stop layer therefore the product is the "Etch Stop Layer"