YES III, HMDS primer oven

To be read first:

  • !  Hot  ! T = 125 °C:  The metal carrier maintains high temperature for several minutes. To move cassettes, use the handle available by the machine.
  • Make sure to include a 25 minutes time interval before the EVG 150 and Ritetrack 88 coater booking period to perform the HMDS treatment.
  • Do not apply HMDS deposition with the YES III primer oven if you coat photoresists using the ACS 200, which has his own HMDS module.
  • Please immediately inform the CMi staff in case of problems with the equipment.


  1. The HMDS ovens are free to use, with no booking and no login.


  1. Introduction
  2. Equipement description
  3. Users manuals
  4. Links
  5. Pictures gallery

I. Introduction

The YES III primer oven allows batch priming of Si, SiO2 (native or film) and SiN with silane molecules, to enhance adhesion of polymers, such as photoresists.

Hexamethyldisilazane (HMDS, CAS Number 999-97-3, Formula C6H12NSi2) is extensivly used for standard novolak photoresists. More details can be found here.

According to the equipment supplier, some other following compounds are commonly used for priming:

  • Trimethylsilyldiethylamine (TMSDEA or DEATS) has a faster reaction time than HMDS but is not in common use for silicon layers; It is preferred for metal layers instead. CAS Number 996-50-9. Formula C7H19SiN.
  • (3-Aminopropyl)triethoxysilane (APTS or AEPTS) is used as priming agent for polyimide coating. CAS Number 919-30-2. Formula C9H23NSiO.

II. Equipment description

Technical characteristics:

Two YES III primer ovens are installed at CMi BM-1:

  • Zone 1 and Zone 6
  • The priming agent is HMDS in vapor phase
  • Temperature = 125 °C
  • Exposure time = 60 sec
  • Total process time including purges = 25 min

Equipment operation:

  • Check that the controller (upper right corner) is not running. The pressure gauge must show atmosphere.
  • Use the designated metal carrier to load wafers (25 slots for 4″ or 6″ wafers per cassette).
  • Open door and load carrier using the handle. Close door.
  • ! Wait 3 minutes ! to allow wafers to heat up to the oven temperature (dehydration starts efficiency at atmospheric pressure).
  • Check thumbwheel to make sure the correct program is selected (see table below).



    Prog. N° (thumbwheel)

    Zone 1


    125 °C


    Zone 6




  • Start run by pressing  “Reset”  followed by “Start”. 
  • Purge begins with a vacuum valve opening. Push lightly the door with one hand during the first 5 sec. until the vacuum gauge starts to display continuous decreasing value!
  • Run cycle is ~25 minutes.
  • At the end of the process an alarm will sound for 1-2 minutes. This can be stopped it immediately by pressing “Reset”.
  • Open door and unload carrier USING THE HANDLE. Close door. The carrier stays outside of the oven in stand-by.
  • Wait 3-5 minutes to allow wafers to cool down to room temperature before proceeding to spin coating deposition.

III. User manuals

IV. Links

V. Pictures gallery