EHT Products for Semiconductor Fabrication

Highest Precision Ion Energy Distribution (IED) | Wafer Bias | Chucking | Plasma Generation

Unipolar and Bipolar| Tightly Controlled Wafer Voltages | Narrow Ion Energy Distributions (IED) | Small Critical Dimensions.

The EHT Semi plasma products achieve the highest semiconductor fabrication etch quality with precision control of the ion energy distribution (IED) at lowest minimum critical dimensions, yet with etching rates comparable to RF generators.

Our product range for semiconductor fabrications is summarized in the following table. Click any link for further information:

Model Applications Uni- or Bipolar maximums: MHz
kV kW A
Spartan™ Wafer bias, Chucking Unipolar 14 20 175 600
Hoplight™ Wafer bias, Chucking Unipolar 18 5 130 600
Perseus™ Wafer bias Bipolar 16 20 110 600
Mid-Freq. RF™ Wafer bias, Plasma generation Bipolar 25 100 3 кА 1
High-Freq. RF™ Wafer bias, Plasma generation Bipolar 10 20 кА 15

EHT Semi products are designed for plasma generation and control during semiconductor fabrication. Our pulse generators are used to improve ion energy distribution control, bias surfaces, and chucking. Our RF generators are designed for direct drive of capacitive and inductive loads, eliminating the need for match boxes in plasma generation and surface bias applications.

Our semiconductor manufacturing product range features:

EHT Semi Products for Wafer Bias

EHT Semi has developed several pulse generators for wafer bias in conductor etch, dielectric etch and atomic layer etch (ALE). These pulse generators allow you to optimize the bias voltage waveform on the wafer to precisely control the IED at the wafer surface to improve your etching process (especially the minimum critical dimension and etch rate). 

EHT Semi Products for Plasma Generation or Wafer Bias

EHT Semi’s matchless RF generators can direct drive the capacitive or inductive load for plasma production or wafer bias. This direct drive ability eliminates the complexity of a matching network and allows the voltage, power, and duty cycle to be tunable in real time. We can design systems that operate at higher voltage and peak power levels compared to traditional RF generators. The higher power translates to faster etching. EHT has developed two classes of matchless RF generators, Mid- and High-Frequency.

The differences between bipolar and unipolar waveforms and the impact on IEDs are discussed in this tutorial.

All of our pulse generators can be customized, or we can build systems specifically for your application.

Feature/Paremeter Spartan™ Perseus™
Polarity  Unipolar positive Bipolar
Maximum Vpk-pk 16 kV into open load (>12 kV into simulated plasma load) >16 kV into simulated plasma load
Wafer On-Time (per-pulse)  ~1.8ps >1.6 µs
Max avg. DC input power 20 kW 25 kW+
Power efficiency  65% (into simulated plasma load) 89% (into simulated plasma load)
Ion Current/Wafer Voltage Droop Compensation Not implemented Active Droop Compensation w/ energy recovery
Edge Ring Driver Compatibility  Separate Supply (e.g. Hoplite) Separate Supply
Continuously Variable Multistate Operation Yes Yes
Size  ~7.5 ft3 (depending on configuration) ~7.5 ft3 (depending on configuration)
Weight ~125 kg (depending on configuration) ~125 kg (depending on configuration)

Product Landscape

The market for wafer bias products, plasma excitation, and RF generators is addressed by Advanced Energy with their eVoS LE and ME Bias Solutions, Comet pct,  MKS Instruments, and Trumpf Hüttinger. 

Potential users of our semiconductor plasma etching products include