Fraunhofer Institute for Electronic Microsystems and Solid State Technologies EMFT
Plasma generator in the Fraunhofer EMFT MEMS (microelectromechanical system) line
MEMS - Micro-Electro-Mechanical Systems
MEMS Development and Production in a Cutting-Edge Cleanroom
Diffusion Processes
| Oxidation | Building up of SiO2 layers 40 nm up to 2 µm thick using wet and dry oxidation, in temperature range between 850 °C and 1100 °C. Wafer sizes of 100 mm and 150 mm can be processed. The processing takes place in Innotherm horizontal oven. |
| Diffusion | Diffusion of dopants and activation of implantations in an inert or oxidizing atmosphere in temperature range between 650 °C and 1150 °C. Wafers sizes of 100 mm and 150 mm can be processed. The processing takes place in Innotherm horizontal oven. |
| Tempering | Forming gas tempering of metals in an atmosphere of nitrogen/hydrogen atmosphere in temperature range between 380 °C and 450 °C. Tempering of metals in an inert or oxidizing atmosphere in temperature range between 380 °C and 650 °C. Wafer sizes of 150 mm and 200 mm can be processed. The processing takes place in Innotherm horizontal oven. Tempering of wafer stacks after silicon fusion bonding at temperatures up to 1100 °C. Wafer sizes of 150 mm and 200 mm can be processed. Drying or tempering of substrates at temperatures up to 400 °C in air, vacuum or N2-atmosphere. Wafer sizes of 100 mm, 150 mm and 200 mm can be processed. The processing takes place in plate-heated Heraeus oven. |
Metallization
| Metal deposition by sputtering – equipment 1 | Vertical sputtering equipment with two chambers, substrate conditioning by inverse sputter etching is possible in the lock. The coating chamber includes four targets for DC magnetron sputtering. Typical metals include Au, Al, Cr, Cu, Ni, Ti and TiW, additional metal targets are available or can be ordered and installed at request. The equipment allows for simultaneous coating of up to 12 wafers size 150 mm or smaller, or up to 8 wafers size 200 mm. Coating of foils or special components is also possible at request. The processing takes place in Balzers LLS801. |
| Metal deposition by sputtering – equipment 2 | Metallization with common metals, metal oxides and alloys (Al, AlCu, Al2O3, SiO2, Cr, NiCr, Ta, Pd, Ag, Ti, WTi and Cu) with specific requirement profiles. Additionally, layers of nitride or oxide can be produced using reactive sputtering processes. Optionally, the substrates can be actively heated during the process. A separate sputter etching chamber is available for etching. Wafers and flat samples up to the size of 200 mm can be processed. The processing takes place in the sputtering equipment CS850S from VON-ARDENNE. |
| Metal deposition by sputtering – equipment 3 | Deposition of e.g. Cu, Nb, Cr, TiN in the temperature range from 50 °C to 600 °C. The layer thickness is adjusted to requirements. The layers can be combined as desired (4-multi-target). 200 mm wafers can be processed. Processing takes place in the Polyteknik Flextura 200. |
Lithography
| Coating | Coating of the wafers with various coatings using a manually loadable spin-coater. Standard coatings include positive-working resists from Microchemicals (AZ 10XT, AZ ECI3007 and AZ ECI3027 - in a special dilution), for layers from 1.5 µm to 8 µm thick. Wafers up to the size of 200 mm can be processed, special substrates upon request. The processing takes place in Süss Spinlab. |
| Drying | Drying of the coatings using Ramgraber hotplate for wafers up to 200 mm and Heraeus convection oven for wafers up to 200 mm in size. |
| Exposure | Various exposure modi such as proximity, soft, hard and low-vacuum contact are possible. The backside-alignment system enables alignment of the mask to the alignment marks on the backside of the wafer. Wafer sizes of 150 mm and 200 mm can be processed, special substrates upon request. The processing takes place in Süss mask aligner MA8Gen3. |
| Special processes | Processing of dry-resists (lamination in laboratory), double-layer lift-off process (under development). |
Dry-Etching
| Reactive etching of dielectric and organic layers, resist stripping | Etching of various organic layers (coatings, dielectrics) and inorganic layers (Si, SiO, SiN, SiC, Nb, NbTin) using a manual RIE system, connected to the process gases O2, CF4 and CHF3 . Due to the manual loading, all substrates and formats up to 200 mm in diameter can be processed. The processing takes place in PlasmaLab 80 from Oxford Instruments. |
Wet Chemical Processes
| Cleaning processes | SC1, SC2 and Caro cleaning as well as SiN etching processes (phosphoric acid) in heatable quartz basins. HF Dip (1 %) and BOE etching of SiO2 layers are carried out in basins. The standard for resist-stripping of positive resists is the AZ Remover 100 (supported by ultrasound). |
| Metal etching | Metal etching (for example Al, Cu, Cr, TiW, Au, Sn) is carried out in beakers. Wafers up to 150 mm in size can be processed in basins, in beakers also 200 mm wafers can be processed. |
| KOH etching | KOH etching in a temperature-controlled wet bench. The etching temperature is 60 °C or 80 °C. Wafer sizes of 150 mm and 200 mm can be processed as single wafers or in batches of 12. |
| TMAH etching | TMAH etching in an automatic etching system. Wafer sizes of 150 mm and 200 mm can be processed as single wafers or in batches of 12. |
In-line Process Analytics
| Microscopy | Microscopy with incident light, dark field and interference contrast, image documentation via camera is possible. Wafer sizes of 100 mm, 150 mm, or 200 mm can be processed with a Leica INM200 microscope. |
| Reflectrometry | Reflectometry at wave lengths of 450 nm to 750 nm, minimum spot size approximately 20 µm. The reflectrometric measuring equipment is connected to Leica INM200 microscope. |
| Profilometry | Measurement of steps from 50 nm to 300 µm. Samples up to 200 mm in diameter can be processed with Veeco Dektak. |
| Measurement of wafer thickness and deflection | Measurement of wafer thickness and deflection using a contactless capacitive method. Samples up to 200 mm in diameter can be processed. The measurement takes place with equipment from the company Eichhorn&Hausmann. |
| Wetting angle | Measurement of the wetting angle by measuring the polar and dispersive components. The processing takes place in the laboratory with equipment from the company DataPhysics. |
| Atomic force microscope | Measurement of surface roughness and step heights up to a maximum of 5.5 μm. Suitable for sample sizes up to 200 mm. Electrical measurement methods possible (C-AFM, KPFM, EMM, etc.). Processing is carried out on the NX20 atomic force microscope (AFM) from Park Systems. |
| Raman spectroscopy | Carried out with equipment of Horiba. |