Efficient BEOL solutions for semiconductor industry

BEOL, the second phase of IC manufacturing, interconnects devices with metal wiring. It commences with the initial metal layer deposition. Siconnex provides an excellent and comprehensive range of semiconductor equipment for all these process steps.

Clean

Post Etch Residue Clean - PERC™

Dry etching steps within BEOL lead to several kinds of polymers. Siconnex’s self-developed Post Etching Residue Clean (PERC™) process enables the complete removal of 100% of these polymers.

Suitable Equipment

Acid
Clean
Acid/Clean
Clean

Post ash clean

When stripping a photoresist via plasma, some residues, known as „ash,“ remain on the surface. Multiple options are available for cleaning these residues, including the use of SicOzone or a solvent-based media, as well as a mixture of sulfuric acid and peroxide.

Suitable Equipment

Acid
Clean
Solvent
Acid/Clean
Acid/Solvent
Clean

Polymer Clean

Polymers generated during dry etching are removed using solvent-based media.

Suitable Equipment

Solvent
Acid/Solvent
Resist Strip

Piranha strip

Highly treated photoresists can be challenging to remove. A mixture of sulfuric acid and peroxide is deployed because of its high temperature and strong acidity, which effectively removes the photoresist. Compatibility with the underlying material is crucial.

Suitable Equipment

Acid
Acid/Clean
Acid/Solvent
Resist Strip

Solvent based Photo Resist Strip

Regardless of resist type (negative, positive, implanted, or treated), solvent-based solutions are used for stripping these resists.

Suitable Equipment

Solvent
Acid/Solvent
Resist Strip

SicOzone Strip

The most cost-effective method for removing photoresist is ozone-based stripping. Ozone-based photoresist stripping is also applicable to exposed metals. Most metals are not affected by ozone as an oxidizer. With various parameter options and expertise, SicOzone can be utilized in the BEOL process.

Suitable Equipment

Acid
Clean
Acid/Clean
Etch

Freckle etch

When wet etching AlSi or AlSiCu, the silicon grains of the alloy can remain on the surface. To remove them, a freckle etch process is performed.

Suitable Equipment

Acid
Acid/Solvent
Etch

Copper seed etch

To electroplate copper, a seed layer is essential. After growth and photoresist removal, it becomes necessary to etch the seed layer. There are several methods available to achieve this removal.

Suitable Equipment

Acid
Acid/Solvent
Etch

Oxide etch

Oxide etching is a crucial step in chip manufacturing. Common etching mixtures include BOE 7:1 or 10:1, BHF, and HF at varying concentrations. The typical uniformity values for this process are as follows: <1% within the wafer, <2% wafer-to-wafer, and <2% batch-to-batch.

Suitable Equipment

Acid
Acid/Clean
Acid/Solvent
Etch

Metal etch

In BEOL processes, materials such as Au, Ag, Al, Cu, Cr, Mo, Ni, Ta, Pt, or salicides are commonly used to establish connections or create various functions. The BATCHSPRAY® processing of these materials combines uniformity, efficiency, and effective process control.

Suitable Equipment

Acid
Acid/Solvent
Etch

Barrier etch

Ti, TiN, TiW, and W are common materials used to create barriers. Often, a stack of more than two layers is used. Various methods are available for removing these layers, and an advantage is achieved by conducting an in-situ etch that addresses all layers in a single, straightforward etch step.

Suitable Equipment

Acid
Acid/Solvent
Etch

UBM etch

Typical stacks, such as Ag, Ni, Ti, or Au Ni, Ti, or Au Cu, Ni, Ti, are deployed to enhance the conductive performance from the chip to the bump. Achieving selective etching of all layers and perfect undercut performance are crucial factors in this process.

Suitable Equipment

Acid
Acid/Solvent
Clean

Photomask Clean

Photomasks, essential in lithography for wafer patterning, need periodic cleaning. Contaminated photoresists on masks up to 9″ square are removed using a sulfuric-peroxide mixture.

Suitable Equipment

Acid

Resist Development

The most common method for developing the resist is immediately after patterning. However, in certain applications, batch development of multiple wafers can be done using typical solutions such as 2.6% TMAH or 3.6% KOH.

Suitable Equipment

Acid
Solvent
Acid/Solvent
Etch

Compound semiconductor etch / CS etch

In the world of compound semiconductors, materials like GaAs, GaInP, AlInP, InP, GaN, and others are commonly used. When it comes to shaping, cutting, and removing these materials, various options are available.

Suitable Equipment

Acid
Acid/Solvent