• Journal of the Semiconductor & Display Technology
• /
• v.18 no.4
• /
• pp.149-153
• /
• 2019

The technology of electronic packaging among semiconductor technologies is evolving as an axis of the market in its own field beyond the simple assembly process of the past. In the field of electronic packaging technology, the packaging of power modules plays an important role for green electric vehicles. In this power module packaging, the thermal reliability is an important factor, and silicon nitride plays an important part of package substrates, Silicon nitride is a compound that is not found in nature and is made by chemical reaction between silicon and nitrogen. In this study, this core material, silicon nitride, was fabricated by reaction bonded silicon nitride. The fabricated silicon nitride was studied for thermo-mechanical properties, and through this, the structure of power module packaging was made using reaction bonded silicon nitride. And the characteristics of stress were evaluated using finite element analysis conditions. Through this, it was confirmed that reaction bonded silicon nitride could replace the silicon nitride as a package substrate.

• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.18 no.4
• /
• pp.137-139
• /
• 2008

Floating zone, neutron transmutation-doped and magnetic Czochralski silicon crystals are being widely used for fabrication power devices. To improve the quality of these devices and to decrease their production cost, it is necessary to use large-diameter wafers with high and uniform resistivity. Recent developments in the crystal growth technology of Czochralski silicon have enable to produce Czochralski silicon wafers with sufficient resistivity and with well-controlled, suitable concentration of oxygen. In addition, using Czoehralski silicon for substrate materials may offer economical benefits, First, Czoehralski silicon wafers might be cheaper than standard floating zone silicon wafers, Second, Czoehralski wafers are available up to diameter of 300 mm. Thus, very large area devices could be manufactured, which would entail significant saving in the costs, In this work, the conventional Czochralski silicon crystals were grown with higher oxygen concentrations using high pure polysilicon crystals. The silicon wafers were annealed by several steps in order to obtain saturated oxygen precipitation. In those wafers high resistivity over $5,000{\Omega}$ cm is kept even after thermal donor formation annealing.

• Journal of the Korean Ceramic Society
• /
• v.41 no.3
• /
• pp.197-201
• /
• 2004

SiO$_2$ and SiON thick films were deposited by Plasma Enhanced Chemical Vapor Deposition (PECVD) technique on silicon wafer (100) using SiH$_4$ and $N_2$O as precursor gases. In this work, the influence of rf power, and rf bias power on the optical and physical properties of SiO$_2$ and SiON thick films is presented. The refractive index decreases with increasing rf power, and rf bias power. The refractive index of the films varied from 1.4493 to 1.4952 at wavelength at 1552 nm, with increasing rf power, the nitrogen content decreases while the oxygen content increases, in a manner that the O/N ratio increases approximately linearly.

• Journal of the Microelectronics and Packaging Society
• /
• v.25 no.3
• /
• pp.21-30
• /
• 2018

Driven by the recent energy saving trend, conventional silicon based power conversion modules are being replaced by modules using silicon carbide. Previous papers have focused mainly on the electrical advantages of silicon carbide semiconductors that can be used to design switching devices with much lower losses than conventional silicon based devices. However, no systematic study of their thermomechanical reliability in power conversion modules using finite element method (FEM) simulation has been presented. In this paper, silicon and silicon carbide based power devices with three-phase switching were designed and compared from the viewpoint of thermomechanical reliability. The switching loss of power conversion module was measured by the switching loss evaluation system and measured switching loss data was used for the thermal FEM simulation. Temperature and stress/strain distributions were analyzed. Finally, a thermal fatigue simulation was conducted to analyze the creep phenomenon of the joining materials. It was shown that at the working frequency of 20 kHz, the maximum temperature and stress of the power conversion module with SiC chips were reduced by 56% and 47%, respectively, compared with Si chips. In addition, the creep equivalent strain of joining material in SiC chip was reduced by 53% after thermal cycle, compared with the joining material in Si chip.

• Journal of Power Electronics
• /
• v.13 no.4
• /
• pp.584-591
• /
• 2013

In this paper, a hybrid booster power module with Si IGBT and Silicon Carbide (SiC) Schottky Barrier Diode (SBDs) is presented. The switching characteristics of the hybrid booster module are compared with commercial Silicon IGBT/Si PIN diode based modules. We applied the booster power module into a non-isolated on board vehicle charger with a simple buck-booster topology. The performances of the on-vehicle charger are analyzed and measured with different power modules. The test data is measured in the same system, at the same points of operation, using the conventional Si and hybrid Si/SiC power modules. The measured power conversion efficiency of the proposed on-vehicle charger is 96.4 % with the SiC SBD based hybrid booster module. The conversion efficiency gain of 1.4 % is realizable by replacing the Si-based booster module with the Si IGBT/SiC SBD hybrid boost module in the 6.6 kW on-vehicle chargers.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 1992.05a
• /
• pp.42-45
• /
• 1992

The poly silicon thin films were prepared by solid phase crystallization at 600$^{\circ}C$ of amorphous silicon films deposited on Corning 7059 glass and (100) silicon wafer with thermally grown SiO$_2$substrate by plasma enhanced chemical vapor deposition with varying rf power, deposition temperature, total flow rate. Crystallization time, microstructure, absorption coefficients were investigated by RAMAN, XRD analysis and UV transmittance measurement. Crystallization time of amorphous silicon films was increased with increasing rf power, decreasing deposition temperature and decreasing total flow rate.

• Proceedings of the KIEE Conference
• /
• 1990.07a
• /
• pp.231-235
• /
• 1990

Soft magnetic silicon steels containing up to 6.5wt% of silicon were prepared by powder metallurgical processing and their magnetic properties were evaluated. The magnetic properties of P/M silicon steels are similarly affected by the silicon addition as those of conventional ingot processed ones but are also significantly affected by density and interstitial impurities particularly oxygen content. Magnetic flux density, $B_{10}$ and coercivity, Hc, tends to decrease with silicon content whereas maximum permeability, ${\mu}m$, decreases first and then increases rapidly above 5 wt% silicon. Increasing density also increases magnetic flux density and maximum permeability but reduces coereivity. The latter two properties are, however, affected more strongly with oxygen content.

• Journal of Information Display
• /
• v.11 no.3
• /
• pp.109-112
• /
• 2010

The solid phase compositions and dielectric properties of silicon nitride ($SiN_x$) films prepared using the plasma enhanced chemical vapor deposition (PECVD) technique at a low temperature ($200^{\circ}C$) were studied. Controlling the source gas mixing ratio, R = $[N_2]/[SiH_4]$, and the plasma power successfully produced both silicon-rich and nitrogen-rich compositions in the final films. The composition parameter, X, varied from 0.83 to 1.62. Depending on the film composition, the dielectric properties of the $SiN_x$ films also varied substantially. Silicon-rich silicon nitride (SRSN) films were obtained at a low plasma power and a low R. The photoluminescence (PL) spectra of these films revealed the existence of nano-sized silicon particles even in the absence of a post-annealing process. Nitrogen-rich silicon nitride (NRSN) films were obtained at a high plasma power and a high R. These films showed a fairly high dielectric constant ($\kappa$ = 7.1) and a suppressed hysteresis window in their capacitance-voltage (C-V) characteristics.

• Proceedings of the KIEE Conference
• /
• 2009.04b
• /
• pp.131-135
• /
• 2009

This paper reviews the characteristics of Power MOSFET device technology that are leading to improvements in power loss for power electronic system. The silicon bipolar power transistor has been displaced by silicon power MOSFET's in low and high voltage system. The power electronic technology requires the marriage of power device technology with MOS-gated device and bipolar analog circuits.

• Korean Chemical Engineering Research
• /
• v.47 no.1
• /
• pp.79-83
• /
• 2009

In this study, the characteristics of amorphous silicon etching for the formation of gate electrodes have been evaluated at the variation of several process parameters. When total flow rates composed of $Cl_2/HBr/O_2$ gas mixtures increased, the etch rate of amorphous silicon layer increased, but critical dimension (CD) bias was not notably changed regardless of total flow rate. As the amount of HBr in the mixture gas became larger, amorphous silicon etch rate was reduced by the low reactivity of Br species. In the case of increasing oxygen flow rate, etch selectivity was increased due to the reduction of oxide etch rate, enhancing the stability of silicon gate etching process. However, gate electrodes became more sloped according to the increase of oxygen flow rate. Higher source power induced the increase of amorphous silicon etch rate and CD bias, and higher bias power had a tendency to increase the etch rate of amorphous silicon and oxide.