。 Slow dry etch rate: significantly slower than PMMA

。 Can be hard-baked: Tg=109℃

。 Can be re-exposed after development

。 Other developers such as IPA:H2O can also be used

。 Shelf life is guaranteed for 6 months

Products – Spin Curves

How it Works - Monte Carlo Simulations

The following Monte Carlo simulations compare the electron scattering behaviour of PMMA and SML resists at 30KeV ａnd at 100KeV. Each simulation contains 500 incident electrons ａnd created secondary electrons are shown in light blue.

Comparison of 50nm thick PMMA & SML on Si substrate exposed @30keV

These simulations show that at both 30KeV ａnd 100KeV:

。 The lateral scattering of incident electrons is much less in SML than in PMMA

。The number of secondary electrons created is much less in SML than in PMMA

These properties mean that SML resist is less susceptible to the problem of proximity effect and enables the patterning of features with smaller critical dimensions, larger aspect ratio, and straighter side-walls, than those obtainable in PMMA resist.

About EM Resist Ltd

EM Resist Ltd specialises in electron beam lithography resists ａnd applications. We develop and manufacture electron beam resists in a purpose built cleanroom facility to ensure maximum quality ａnd performance. We also have a dedicated team of applications scientists to aid our customers with their questions ａnd requirements.

Our products ａnd expertise are the result of many years research by experienced physicists and material scientists in both academia ａnd industry. We are based in Macclesfield, UK ａnd have global sales ａnd distribution channels for our products.

SML Resist – Processing Information

Introduction

SML resist has been specifically designed for electron beam lithography. It is a polymer material and can be processed in exactly the same way as other polymer resists such as PMMA or ZEP. 

Storage

Do not refrigerate.

Store at room temperature.

Store away from direct sunlight ａnd ignition sources.

The shelf life is guaranteed for six months.

Typical Processing Conditions

The processes outlined below are our standard processes. Other common resist processes can also be used.

Substrate Preparation:

Solvent clean with Acetone ａnd IPA.

SML has excellent adhesion to most substrates so HMDS is not generally required.

Spin Coating:

See spin curves below.

Baking:

Hot plate @ 180 C for 120-180 seconds.

Exposure:

Development:

MIBK:IPA （1:3） for 30 seconds, followed by a rinse in IPA for 15 seconds.

Hard-Bake:

Convection oven @ 80 C for 30 minutes. （Tg=109℃ ）

Remover:

Acetone.

Spin Curves

Spin coater settings:

。Ramp up time = 5 seconds.

。Spin time = 20 seconds.

。Ramp down time = 10 seconds.

Safe Handling ａnd Disposal

Caution: Flammable liquid.

Open in a well ventilated area.

Avoid inhalation.

Avoid direct contact with skin ａnd eyes.

Wear appropriate safety equipment such as glasses ａnd gloves.

In case of direct contact with eyes, rinse thoroughly with water ａnd seek medical advice.

Read the Material Safety Data Sheet.

Dispose of in appropriate waste containers for non-halogenated waste.

About EM Resist Ltd

EM Resist Ltd specialises in electron beam lithography resists ａnd applications. We develop and  manufacture electron beam resists in a purpose built cleanroom facility to ensure maximum quality ａnd performance. We also have a dedicated team of applications scientists to aid our customers with their questions ａnd requirements.

Our products ａnd expertise are the result of many years research by experienced physicists and material scientists in both academia ａnd industry. We are based in Macclesfield, UK ａnd have global sales ａnd distribution channels for our products.

100 KeV Exposure Parameters

Please note that the best results （aspect ratio ａnd resolution） are generally achieved when a relatively low beam current is used.

100 KeV Exposure Parameters

30 KeV Exposure Parameters

25 KeV Exposure Parameters

SML Resist – Contrast & Sensitivity

SML – A Complete Solution for you – Part 1 / 2