For most photoresists and Si substrates, their adhesion is generally good. However, in photolithography, substrates such as sapphire, gallium nitride, gallium arsenide, and even precious metal thin films are often used. The adhesion between these substrates and photoresists is often not ideal, which can lead to problems such as "cracks" or even photoresist drift in the subsequent photolithography development process. Therefore, it must be improved through technological means, which we call adhesion enhancement treatment or adhesion aid.

Silicon dioxide, which exists in the form of oxides on quartz, glass, or silicon surfaces (natural oxidation), and most metals form polar OH bonds on their surfaces after being exposed to atmospheric humidity for a sufficient period of time. This substrate is hydrophilic, therefore it has poor affinity for non-polar or low polarity resin molecules of photoresist. In order to make the surface of such a substrate hydrophobic, non-polar molecules such as HMDS can be chemically attached to its surface.

HMDS binds with Si atoms on an oxygen free surface and with oxygen atoms on the oxidized surface (if necessary, OH groups decompose), releasing ammonia. Non polar methyl groups directly isolate the substrate surface to form a hydrophobic surface, which has good wettability and adhesion with photoresist.

Working Principle:

At room temperature, HMDS vapor is transported in a "bubbler" through dry nitrogen gas and then transferred to a heated (75-120 ° C) substrate, where HMDS acts as a monolayer film for chemical bonding on the substrate surface.

If liquid HMDS is directly spin coated onto a substrate, the HMDS layer can only serve as a physical adhesive layer and cannot improve adhesion; Secondly, the HMDS layer releases ammonia during the pre baking process, which enters the cross-linked photoresist layer near the substrate, thereby suppressing the development process.

Product Features

Appearance structure:

The shell is made of A3 cold-rolled steel plate cut, polished, acid washed, phosphating and other surface anti rust treatments, and then baked with paint. The workshop uses SUS316 # clean stainless steel plate fully welded and sealed for high temperature resistance, with a reinforced structure to ensure that the box does not deform under high pressure.

The studio has high airtightness, with a gas leakage rate of up to 100pa/h.

★ Double layer explosion-proof tempered glass observation window, 10mm explosion-proof glass inner door.

The insulation layer adopts 100mm thick 100K high-density aluminum silicate fiber insulation material, with excellent insulation effect.

★ The door frame is sealed with fluorine free silicone rubber sealing strip, which is resistant to high temperature and aging.

Temperature control system:

★ Stainless steel opposite sex heater, surrounding the outer wall of the studio and heating on all sides.

★ 7-inch human-machine interface, PLC+PID+SSR control, SSR non-contact periodic pulse width adjustment, PID intelligent calculation, automatic constant temperature, over temperature suppression, sensor disconnection alarm, power-off memory, precise temperature control, easy operation.

★ Multiple operating modes can be set according to the process

★High precision PT100 stainless steel armored platinum resistance temperature sensor

safety system:

★ Button lock

★ HMDS liquid level alarm

★ Over temperature protection

★ Current overload protection

★ Phase sequence protection

★ Leakage protection

★ Grounding protection