YIELD Engineering Systems Inc.

Chemical Vapor Deposition (CVD) is a process widely used in the semiconductor and biotechnology industries for the deposition of a thin film of various materials in order to achieve surface modification. CVD enables nano-precise surface tension control of your process. Whether you need a slick (hydrophobic)surface coating for microelectromechanical systems (MEMS) or a sticky (hydrophilic) surface for semiconductor or microarray processing, chemical vapor deposition is especially suited for achieving precise, repeatable results.
Complete dehydration followed by CVD coating provides a superior silane/substrate bond that is stable after exposure to atmospheric moisture, extending the time available between process steps. Chemical usage for a vapor deposition process is typically less than 1% of the amount needed for wet application processes, significantly reducing waste and chemical costs.

YES chemical vapor deposition (CVD) systems are designed to provide engineers with complete parameter control over their surface modification processes.

  YES 1224 chemical vapor deposition (CVD) system

The CVD process begins with vacuum chamber cycle purges to prepare the product. The chamber is evacuated to low pressure and refilled with pure nitrogen several times to completely remove water vapor. Nitrogen is preheated, which helps heat the product.
Once cycle purges are finished, the YES-1224 system pumps the chemical directly from the source bottle to the heated vaporization chamber - without exposing the chemical to moisture.
YES-1224 accommodates two chemical source bottles as well as wide variations of vapor pressures among different silanes. Processes are easily programmed using a touch screen operator interface.

YES-1224 can also be used as a silylation oven. This process enables the use of short wavelength radiation -with its attendant shallow depth of field - to define high-resolution photoresist topographies.
The process requires exposure of the photoresist layer using a standard process with a reverse mask of the circuit. The wavelength is used to irradiate the top level of exposed photoresist. Now, the substrate is moved to the silylation oven to be exposed to HMDS vapor. Indene-carboxylic acid generated where the photoresist was exposed then combines with HMDS vapor, impregnating the shallow surface layer with pure silicon.
In the subsequent oxygen plasma process, this silicon layer forms an effective mask and is converted to silicon dioxide. The plasma removed only the unexposed photoresist, leaving a high resolution profile of the defined circuit.

YES-1224 gives process engineers parameter control over:

Cleanliness

Class 10 clean room

Chamber Material

316L stainless steel

Chamber Size

16" (406 mm) H x 16" (406 mm) W x 18" (460 mm) D

Loading

4 removable internal stainless steel shelves with 16 available positions

Capacity

8 cassettes of 100mm - 150mm wafers
2 cassettes of 200mm - 300mm wafers

Temperature

Up to 205°C chamber temperature

Uniformity

Chamber uniformity +/- 5°C (after stabilization period)

Throughput

Typical process 1-2 loads/hour. Varies by process.

Safety

Audible and visual alarms. Redundant over-temp monitoring.

Chemical Usage

Typical process 3-5 ml

Chemical Volume Control

Control down to 0.1 ml

Power Domestic (USA)

208V, 60 Hz, 1 phase, 20 A

European (EU)

230V, 50 Hz, 1 phase, 20 A

Exterior Dimensions

40-23/32" (1043mm) H x 38-3/4" (984mm) W x 36" (914mm) D
(not including light tower)

Shipping Weight (Crated)

Approx. 1250 lbs (567 Kg)

YIELD ENGINEERING SYSTEMS INC.

SURFACE TENSION MODIFICATION FOR THE BIOTECH, DNA AND BIOCHEMISTRY INDUSTRY
The process begins with vacuum chamber cycle purges to prepare the product. The chamber is evacuated to low pressure (about 10 torr) and refilled with pure nitrogen several times to completely remove water vapor. This is the same process as our standard Vacuum Bake /Vapor Prime systems. This process replaces all room air with preheated nitrogen, which also helps to heat the product. After the cycle purges are complete, there is a programmable stabilization period at low pressure (about 1 torr) to complete substrate dehydration and to ensure that the product substrates are brought to temperature (longer stabilization periods are recommended for larger/thicker substrates). The YES-1224 system then pumps the silane chemical directly from the source bottle to vaporization chamber without exposing the chemical to heat or air. 
A nitrogen purge in the source bottles helps to ensure that chemicals are not degraded by exposure to atmospheric oxygen. The chemical remains at room temperature until it is needed. The YES-1224 accommodates two chemical source bottles; the two chemicals may be either the same or different. The system may be programmed to mix multiple chemicals or to automatically draw from the second source bottle while the first bottle is being replaced. All of this is easily programmable through the touch screen operator interface. The chemical is sent in metered amounts to the vaporization chamber where it is flash vaporized. The vapor flows into the process vacuum chamber and into contact with the preheated and fully dehydrated substrates. The process engineer has control of the amount of liquid, the speed of liquid injection, vaporization chamber temperature, vapor line temperature, process vacuum chamber temperature, process starting pressure, and exposure time. This allows the system to accommodate the wide variation of vapor pressures among the different silanes. 
After exposure to the silane vapor, the vacuum chamber is again cycle purged several times with nitrogen to remove all vapor from the chamber before the door is opened for unloading. The YES- 1224 includes a vapor trap on the vacuum exhaust line to prevent silane chemical from entering the vacuum pump. Wetted materials for the YES-1224 are 300 series stainless steel, Teflon, and a chemically resistant Vespel.

YES 1224

YES 1224 Complete Details
Complete Brochure of Model YES-1224
Surface Tension Mod. for the Biotech Industry