Abstract: A fan structure is disclosed to include a fan holder holding a fan motor and a fan blade, a bottom cover frame, which has smoothly arched bottom wall, a horizontal mounting flange extending around the smoothly arched bottom wall and mounted in one frame sash of a light steel structure of a ceiling, a vertical connection flange connected to the top cover shell of the fan holder, a circular center opening corresponding to the fan blade, ventilation holes spaced around the circular center opening and a fence disposed above the circular center opening and surrounding the fan blade defining with the top cover shell of the fan holder a space for causing a gate effect during rotation of the fan blade, and a grille mounted in the circular center opening of the bottom cover shell for output of currents of air caused by the fan blade.

Abstract: A method of lowering the dielectric constant of an organosilicon low k dielectric layer while improving the hardness and thermal stability is provided. A deposited layer of carbon doped oxide, HSQ, or MSQ is cured and treated with a He plasma which improves hardness for a subsequent CMP step and lowers the dielectric constant. There is no loss of H2O or CH4 during the He treatment. The low k dielectric layer is then treated with a H2 plasma which converts some of the Si—O and Si—CH3 bonds near the surface to Si—H bonds, thereby further lowering the dielectric constant and increasing thermal stability that improves breakdown resistance. Moisture uptake is also reduced. The method is especially useful for interconnect schemes with deep sub-micron ground rules. Surprisingly, the k value obtained from two different plasma treatments is lower than when two He treatments or two H2 treatment are performed.

Abstract: A damascene structure and method for forming the same in a multi-density dielectric insulating layer the method including providing a substrate; forming at least a first layer comprising silicon oxide according to a first process having a first density; forming at least a second layer comprising silicon oxide according to a second process over the first layer having a second density less than the first density; etching a damascene opening through a thickness portion of the at least a first and the at least a second layer; and, filling the damascene opening to form a metal filled damascene.

Abstract: A method of lowering the dielectric constant of an organosilicon low k dielectric layer while improving the hardness and thermal stability is provided. A deposited layer of carbon doped oxide, HSQ, or MSQ is cured and treated with a He plasma which improves hardness for a subsequent CMP step and lowers the dielectric constant. There is no loss of H2O or CH4 during the He treatment. The low k dielectric layer is then treated with a H2 plasma which converts some of the Si—O and Si—CH3 bonds near the surface to Si—H bonds, thereby further lowering the dielectric constant and increasing thermal stability that improves breakdown resistance. Moisture uptake is also reduced. The method is especially useful for interconnect schemes with deep sub-micron ground rules. Surprisingly, the k value obtained from two different plasma treatments is lower than when two He treatments or two H2 treatment are performed.