Fabrication of Medium Power Insulated Gate Bipolar Transistors Using 300 mm Magnetic Czochralski Silicon Wafers

Abstract

The use of silicon wafer substrates with a diameter of 300 mm for the manufacturing of electronic devices strongly increases the overall productivity of a device manufacturing line. However, float‐zone (FZ) silicon, which is traditionally used for insulated gate bipolar transistors (IGBTs), is not available for wafer diameters exceeding 200 mm. Therefore, a silicon material fabricated by the magnetic Czochralski (m:Cz) method has to be used for IGBT production on 300 mm wafers. Critical issues of this material are the so‐called crystal originated particles (COPs) and the strong axial variation of the doping level along the crystal. Furthermore, the m:Cz material contains a relatively high concentration of oxygen so that the influence of carbon/oxygen complexes has to be considered. CIOI complexes can be decorated with hydrogen atoms, resulting in donor‐like complexes. In particular, the application of proton irradiation for the doping of the field‐stop zone results in a relatively high concentration of interstitial carbon, which is continuatively associated with the generation of undesired donors. It is shown that the electrical behavior of IGBTs fabricated on FZ substrates can be well reproduced using the m:Cz material if the parameters of the hydrogen implantation are adjusted appropriately.

Impact of Defect Engineering on High‐Power Devices

“…The motivation for more proton energies is the flexibility to adjust a wider field stop profile with softer turnoff without voltage overshoots and oscillations. [ 23,24 ]…”

“…Nowadays, one can find industrial IGBTs utilizing the multienergy proton implanted hydrogen buffer produced at 150 and 200 mm FZ NTD as well as on 300 mm m:CZ wafers. [23,24] The proton implanatation is composed of three different energies between 0.5 and %1.1 MeV with three different doses ranging between 1.10 12 and 1.10 14 cm À2 . The motivation for more proton energies is the flexibility to adjust a wider field stop profile with softer turnoff without voltage overshoots and oscillations.…”

“…The motivation for more proton energies is the flexibility to adjust a wider field stop profile with softer turnoff without voltage overshoots and oscillations. [23,24] The state-of-the-art industrial 1200 V silicon IGBTs are qualified up to the maximal junction temperature T jmax ¼ 175 C. The technology and design of the field-stop buffer plays a dominant role in achieving this limit. The buffer constitutes the key N-type part of the emitter-base P-N junction of the internal P-N-P transistor, which determines the amplification of leakage current by transistor effect.…”

Fabrication of IGBTs using 300 mm magnetic Czochralski substrates

“… Overcurrent turn‐off transients I C (t) and V CE (t) of 1200 V IGBTs fabricated in 200 mm FZ‐wafer and 300 mm MCZ‐wafer technology for 10 × I nom , 600 V DC‐link voltage at 150°C (from [14])…”

Evaluation of thermally activated defects behaviors in nitrogen-doped Czochralski silicon single crystals using deep level transient spectroscopy

“…Simultaneously, the transfer to 300 mm diameter wafers has started in Europe to improve productivity. 2,3) However, it might be difficult to enlarge crystal diameters using the FZ method, but using the Czochralski method, it is relatively easy to grow 300 mm diameter crystals. Therefore, it is necessary to develop a growth technique for 300 mm diameter Si single crystals manufactured using this method (Cz-Si) to replace FZ-Si in IGBTs.…”