Plasma Ashing & Stripping (Photoresist Removal)

SAMCO Inc. > Featured Solutions > Plasma Ashing/Stripping/Removal of Photoresist

Semiconductor device production processes are getting more complicated in order to achieve high performance, and lithography is one of the key processes for next-generation devices. Related with the lithography process, photoresist removal after etching or ion implantation is a critical process in device production.

There are various demands for photoresist removal process.

• Low-damage process

• High throughput for mass production

• High etch rate

Samco offers photoresist removal solutions to meet customer’s demands, using plasma etching and UV-Ozone technologies. These technologies can be used not only for general photoresist stripping but also for removal of post-etch polymer residue, which is formed as by-product during plasma etching process.

Photoresist Stripping

 Plasma Ashing of Photoresist

Low-damage Ashing

The plasma ashing process uses ions and radicals generated by a plasma. Reactive Ion Etching (RIE) process uses the ions and radicals for effective photoresist removal. While ions bombard physically to remove photoresist by sputtering, radicals chemically react with the photoresist surface to create volatile molecules such as H2O and CO2. The combination of these two mechanisms is a key of the plasma ashing by RIE etching. One of the drawbacks of RIE etching process is the possibility of plasma damage on the substrate due to reactive ions which can directly attack the substrate surface and cause physical damage and charging.

Samco’s plasma cleaners are equipped with three different modes depending on shelf position settings.

Reactive Ion Etching (RIE)
Mode

SAMCO RIE Mode of Plasma Cleaner

Samples are placed on the powered electrode. Ions induced by RF power directly attacks the substrate, and they will increase the etch rate.

Plasma Etching (PE)
Mode

SAMCO Plasma Etch Mode of Plasma Cleaner

Samples are placed on grounded electrode. While ions do not attack the substrate, radicals react with the surface. This configuration eliminates the risks of plasma damage caused by ion bombardment.

Downstream
Mode

SAMCO Downstream Mode of Plasma Cleaner

A perforated electrode is placed above samples to isolate them from the plasma and minimize plasma damage.

These three shelf configurations will mitigate plasma damage issue while maintaining etch rate. Various photoresist materials can be completely removed including SU-8, PMMA and Novolac resin.

From 100 mm to 450 mm

Samco offers plasma ashing solutions for multiple-size wafers from 100 mm to 450 mm.
Optional stage heating will enhance the etch rate.

Bench-top Plasma Cleaner

Bench-top plasma cleaners, capable of batch wafer processing with low Cost of Ownership (CoO)

Plasma Asher Chamber

Cassette-loading RIE systems for production

ICP etch systems for higher etch rate

RIE systems for plasma depassivation of 300 mm

Large-chamber systems for 300 mm and 450 mm

 UV-Ozone Ashing of Photoresist

Samco provides UV-Ozone ashing process solutions as well as plasma ashing.
UV-Ozone ashing processes are dry processes and do not require solvent. Additionally, the UV-Ozone ashing processes use only oxygen radicals. The neutral radicals will not cause any physical and charging damages which can be challenges in plasma ashing processes due to strong ion bombardment. Therefore, UV-Ozone ashing offers superior photoresist ashing on damage-sensitive layers and materials such as low-k dielectrics.

High-speed Ashing

Unlike conventional UV-Ozone cleaners, Samco’s UV-Ozone cleaners are equipped with an ozone generator to provide a higher ozone concentration and a sample stage heater to allow process temperature control from ambient to 300°C.
These features increase the reactive oxygen species during the process and improve the etch rate.

UV
+
Ozone
+
Stage Heating
UV/Ozone Photoresist Ashing 1

Stage Temperature vs. Photoresist Etch Rate

photoresist ashing in uv ozone treatment

Stage Temperature vs. Photoresist  Etch Rate

From 100 mm to 300 mm

SAMCO offers UV-Ozone ashing solutions from 100 mm to 300 mm. Optional cassette-to-cassette wafer loading is available for production.

Bench-top UV Ozone System

Table-top UV-Ozone cleaner with low Cost of Ownership (CoO)

open load uv ozone cleaner

UV-Ozone cleaner for 200 mm or 300 mm wafers

Fully-automated cassette-to-cassette wafer loading

Fully-automated cassette-to-cassette wafer loading improves throughput.

 The Value of Samco’s Processes

Advantage of SAMCO process solutions

Meet various demands

Samco’s plasma ashing and UV-Ozone technologies meet various process requirements.

Advantage of SAMCO process solutions

Customer-proven solutions

Samco’s processes have been used for R&D and production.

Advantage of SAMCO process solutions

A wide range of system lineup

Samco offers photoresist removal solutions from 100 mm to 450 mm.

System Lineup

Plasma Cleaners

– for R&D and production



Plasma Cleaner for SAW Device Manufacturing

RIE Systems

– for high throughput



RIE System Chamber

UV-Ozone Cleaners

– for R&D and production



UV-Ozone System for Photoresist Ashing
Contact SAMCO for more product information
Any questions? Contact us for more detail.
Contact SAMCO for more product information
Any questions? Contact us for more detail.
Contact SAMCO for more product information
Any questions? Contact us for more detail.
Contact SAMCO for more product information
Contact us for more detail.
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