Plasmalab 80Plus

Applications include:

• SiO₂, SiNx and quartz etch
• Metal etch
• Polyimide etch
• High quality PECVD of silicon nitride and silicon dioxide for photonics, dielectric layers, passivation and many other application
• Hard mask deposition and etch for high brightness LED production
• Failure analysis dry etch de-processing using the specially-configured PlasmalabμEtch tools, with RIE, dual mode RIE/PE and ICP-processes ranging from packaged chip and die etch through to full 300 mm wafer etch
• III-V etch processes (with optional glovebox to enhance safety of toxic gas use)

Easy open access

• Clear access to the lower electrode and smooth,  particle-free chamber opening operation is provided by the reliable pneumatic hoist mechanism

High performance processes

• Enhanced process uniformity and rates are guaranteed by using a high-conductance radial (axially symmetric) pumping configuration

• Optimised plasma conditions are enableв by three levels of control of matching capacitor values:

• Easy, automatic plasma generation using full automatic matching network
  
• Faster switch-over between widely differing processes using the range og preset capacitor values

• Process fine-tuning and diagnostics through the use of recipe-settable capacitor values in the PC2000TM

• A close-coupled turbo pump provides high pumping speed and excellent base pressure

The addition of datalogging of the capacitor values offers traceability and history of chamber and process conditions.  A close-coupled turbo pump provides high pumping speed and excellent base pressure Easy maintenance  Easy access to main components for maintenance through removable panels on each side Substrate temperature control Substrate temperature control is provided by a range of fluid-cooled and/or electrically-heated electrodes, with a temperature range up to 400 ºC and excellent electrode temperature control and stability  On the Plasmalab80Plus can be further extended down to – 150 ºC with the cryogenic electrode option, enabling Si cryo-etch processes PECVD stress control  Stress control in PECVD is provided by selectable or mixed high/low frequency plasma power, enabling deposited films to be tuned for tensile, compressive or low stress

Helium "cooling" (thermal contact)

ICP65 source  with ESS

Laser interferometry/optical emission

Nitrogen Glove Box

Helium "cooling" (thermal contact)

 ICP65 source  with ESS

typical process pressure: 1 - 100 mtorr plasma density: ca 5 x 1011 / cm2 RF ("self") bias forms at the substrate electrode Ion Energy (~ RF bias) dependent on the RF table power Ion Current (Plasma Density) dependent on ICP power Typical Applications: low damage etching of 3-5's high rate anisotropic etch of Si for MEMS applications high rate SiO2 etching sputter etching applications (Au, Pt)     effective electrostatic shielding to avoid the capacitive coupling component (wall sputtering/ substrate bombardment)

current density vs ICP power with/ without electrostatic screen (at 7 mtorr)

lower (substrate) electrode RF driven substrate electrode cooled thermal contact by He backside cooling automatic height adjustment of the substrate electrode gas inlet through source and through distribution ring high conductance pipework parameter: gas flows, pressure, ICP power, table power similar, older technology: ECR

• increased wall sputtering (contamination on the wafer, decreased wall lifetime/ implosions)
• increased ion bombardment on the wafer (increased ion induced damage)
• possibility of generator "cross talking" (instable plasma)

Laser interferometry/optical emission

The "single beam" laser interferometer is recommended for in situ rate/ depth measurements.
It is often used in the "reflectance mode", where we just monitor changes in the surface reflection.
It can also be used in the "interferometric mode" , where interference signals from two interfaces (e.g. the top of a transparent layer and its bottom or the bottom of an etch and the coated substrate backside).

In-situ etch rate monitoring
Endpoint does not require etch stop layer
Endpoint can be chosen anywhere within the layer once etch rate has been established.

675 nm is the standard wavelength for laser interferometry.
However, for certain III-V applications, e.g. InP-related materials, 905 nm is often more suitable, since the index contrast between InP-related materials is greater (and absorption is lower) at 905nm.
A 905 nm laser endpoint system with high gain amplification of endpoint signal is available from OPT for these demanding endpoint applications.
For GaAs VCSEL DBR stack etching, it is common to use a 675 nm laser interferometer, since this gives
a clearer endpoint trace, typically with each ‚ripple’ relating to each layer within the structure.
For thicker GaAs layers (> about 0.5 microns of GaAs film thickness) 905 nm is typically recommended, since absorption of the laser light is much lower at this wavelength.
Laser endpoint traces can be modelled by OPT for any stack of materials, allowing optimum choice of laser wavelength for any given endpoint requirement.

With laser interferometry it is often useful to run a simulation first and compare this with the actual data real time.	measured data

Optical Emission

Nitrogen Glove Box