1993 Fiscal Year Final Research Report Summary
Development of New Fluidized-bed processes for Si-based Materials
| Project/Area Number |
03555174
|
|---|
| Research Category |
Grant-in-Aid for Developmental Scientific Research (B)
|
| Allocation Type | Single-year Grants |
|---|
| Research Field |
工業物理化学・複合材料
|
|---|
| Research Institution | Faculty of Engineering, Seikei University |
|---|
Principal Investigator |
KOJIMA Toshinori Faculty of Engineering, Seikei University Associate Professor, 工学部, 助教授 (10150286)
|
|---|
| Co-Investigator(Kenkyū-buntansha) |
UEYAMA Korekazu Faculty of Engineering Science, Osaka University Associate Professor, 基礎工学部, 助教授 (10092149)
UEMIYA Shigeyuki Faculty of Engineering, Seikei University Research Associate, 工学部, 助手 (60221800)
|
|---|
| Project Period (FY) |
1991 – 1993
|
| Keywords | Fluidized-bed / CVD / Particle coating / D.C.Plasma / Microwave plasma / Silicon carbide |
|---|
| Research Abstract |
For the development of novel particle processing such as particle coating, utilization of fluidizing phenomena of particles under plasmatic conditions is available. Coating of SiC on the surface of particles from SiH_4 and CH_4 was studied using a D.C.plasma jetting fluidized bed reactor, consisting of fluidized bed superimposed on a D.C.plasma generator. SiH_4 and CH_4 were introduced through the ports forming vortex flow around the plasma jet. Two types of gas injection methods, premix and diffusion-mix methods, were compared. The diffusion-mix method gave high conversions of SiH_4 and CH_4, compared with the premix method. Though fine beta-SiC powder was trapped in the filter installed on the way of exit line, deposition of SiC on the bed particles was not confirmed by X-ray diffraction, probably due to the coating of amorphous or very thin SiC.The elemental analysis along the cross section of the coated particles showed that most silicon was deposited inside the particles and not near the surface. It can be speculated that the reaction gases excited in plasma were diffused into the particles and deposition occurred inside the particles.
Fundamental characteristics of a microwave plasma-fluidized bed reactor for particle processing were also investigated. Alumina or polycrystalline silicon was used as a bed material. Fluidizing phenomena and stability of plasma state seem to depend on the kinds of plasma gas and the level of dielectric loss of particles. Optical observation showed that plasma was generated within bubbles in the bed. Methane conversion was carried out as a model reaction. Although the level of methane conversion in the presence of particles was lower than that in the absence of particles, methane was effectively converted to carbon in the microwave plasma-fluidized bed.
|
