Questions II, problem 31-35 (2 points each)
Try to help complete the Spin Coating Process Description by filling the answers in.
        A typical spin process consists___31__  a dispense step in which the resin fluid isdeposited onto the substrate surface, a high-speed spin step to thin the fluid, and adrying step to eliminate excess solvents __32__ the resulting film. Two commonmethods of dispense are Static dispense, and Dynamic dispense.
Static dispense is simply depositing a small puddle of fluid on or near the centerof the substrate. This can range from 1 to 10 ml depending on the viscosity of thefluid and the size of the substrate to be coated. Higher viscosity and or largersubstrates typically require a larger puddle to ensure full coverage of the substrateduring the high-speed spin step. Dynamic dispense is the process of dispensing whilethe substrate is turning__33__ low speed. A speed of about 500 rpm is commonlyused during this step of the process.
This serves to spread the fluid__34__the substrate and can result in less wasteof resin material since it is usually not necessary to deposit as much to wet the entiresurface of the substrate. This is a particularly advantageous method when the fluid orsubstrate itself has poor wetting abilities and can eliminate voids that may otherwiseform.
 After the dispense step it is common to accelerate to a relatively high speed tothin the fluid to near its final desired thickness. Typical spin speeds for this step rangefrom 1500-6000 rpm, again depending on the properties of the fluid as well as thesubstrate. This step can take from 10 seconds to several minutes. The combination __35__ spin speed and time selected for this step will generally define the final filmthickness.
【題組】31.
(A) in,
(B) from,
(C) at,
(D) of,
(E) to