CAIBE (Oxford Ion Mill)
This is an Oxford Instruments PlasmaLab 300 IBE/RIBE/CAIBE system used for ion beam etching of a variety of materials including metals, oxides, semiconductors. Ion beam etching allows control of sidewall etch profiles by tilting and rotating the sample during the etch. Reactive chemistry is used, when appropriate, to enhance the etch rate of materials, such as oxides, polymers, and semiconductors.
This system is used to ion beam etch noble and inert metals with Ar ion milling and to etch other materials that react with chlorine, fluorine, or oxygen using a reactive ion beam. The ion beam is generated in a 15cm 3-grid ion source manufactured by Oxford. Ion beam voltage and ion beam current control the etch rate. Beam voltage affects the sputter yield (atoms etched per incident ion) and Ion beam current controls the flux of ions. Etch rate should be roughly linear with current. Neutralizing electrons are generated by a plasma bridge neutralizer (PBN) so that sampels are not charged by ions during the etch. Samples can be cooled to 5C or heated to 300C for etching. He back-side cooling is used to transfer heat from(to) the sample to(from) the cooled(heated) platen.
The system is clustered with 2 Oxford ALD systems, allowing the process flexibility of etching followed by ALD passivation or metalization without breaking vacuum.
- Etch gases include: CF4, Cl2, Ar, O2
- Cl2 available in CAIBE mode (Cl2 not entering ion gun) through a gas ring.
- RIBE (reactive gas entering ion gun during RF discharge) mode for all reactive gases
- Low 1 E -7 Torr ultimate chamber pressure, etch pressure ~1 E-4 Torr
- 15cm ion-gun with PBN neutralizer
- Angled etch control from 0 degrees (normal incidence) to 75 degrees.
- Sample Rotated or fixed at controlled position for etching.
- Vb from 50V to over 1000V
- Ib up to 500mA
- He-backside cooling
- Substrate temperature 5C to 300C
- Sample size from 6" wafer to pieces (using holders)
- Clustered through vacuum chambers with ALD systems.
- Masking material depends on material being etched and etch gas used