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'Mask' simply is an arrangement of opaque & transparent areas, that is used to bear a 'pattern' in VLSI 'Patterning' process.
As we know, an IC is a combination of various 'layers' of silicon, each having a certain function in the big picture. Now in Patterning process, a bare silicon wafer is selectively exposed by patterning the insulating coating (silicon dioxide) on top. To pattern the SiO2, we use an 'organic photo-resist' layer, on top of SiO2. The 'mask' contain the design we want, where we want to expose Silicon. So, first we place the mask & pattern the resist (through UV/X-ray, Organic acid, etc etc) and then we pattern the SiO2 that has been exposed now. Resist will be completely removed later.
There are positive & negative Masks also, considering the opaque & transparent regions.
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What is price masking?
Price masking is when the OEM (Original Equipment Manufacturer) hides component pricing from the EMS(Electronics Manufacturing Services) providers through a variety of means, including buy/sell agreements and rebates. For the OEM, price masking allows the negotiations between it and the supplier to occur in private and can actually improve supply assurance during times of allocation. However, price masking can be difficult and expensive to implement and it has productive benefits of establishing price masking concepts - 1. Products can be purchased for a best price from the supplier and sell it to market price to the contract manufactures. 2. Allows rebate discounts etc., Hope above information may help you Vinod.
Is vitiligo curable 100 percent?
According to American Vitiligo Research Foundation no cure is available for this disease. The main of goal of vitiligo treatment is to stop or slow down the progression rate of de-pigmentation. Some treatments are also available for re-pigmentation.No; vitiligo cannot be cured at this time but there are several treatment options available with varying results, depending on the amount of pigment loss. The use of sunscreen is vitally important, not only to save the skin from damage but to prevent more discoloration.Temporary treatmentsConcealer: There are cosmetics that can be used to blend out areas with pigment loss, ranging from very heavy masking used for people who have facial scars to the new lighter air brushing and mineral make-up.Surgical treatmentsMedical Tattooing or micropigmentation: Can be effective around lips or on people with dark skin. Cons - tattoos fade, don't tan and may not match well.Blister grafting: After creating suction blisters of equal size and shape, the top skin from a pigmented area replaces skin in an area without pigment. Creates less scarring than other grafts or transplants. Cons - may leave a cobble stone appearance, the pigment may not "stick".Autologous skin (using your own tissue) grafting: used if you have small patches of vitiligo. Patches of pigmented skin are transplanted to areas without pigment. Cons - scarring, spotty skin color or failure to repigment.Medical TreatmentsCorticosteroids (Topical): Started early this may help repigment your skin. Treatment is effective and easy. Lower doses can be used when there is large areas to be treated. It takes up to 12 weeks to start seeing effects. Cons - Needs frequent monitoring for side effects by MD.Immunomodulators (Topical): Pimecrolimus and tacrolimus ointment (can be) used with UVB treatment. Effective for small areas on face and neck. Fewer side effects thancorticosteroids. Cons - Only small studies done. May increase risk of skin cancer and lymphoma.Photochemotherapy (Psoralen plus UVA) PUVA Topical: Exposure to UVA light after topical psoralen. For less than 20% total depigmented patches. Treatment done twice weekly, causes skin to turn pink then heals with more normal appearing color. Cons - can cause burn, blister and temporary hyperpigmentaion.Narrowband UVB: Phototherapy 3 times weekly, similar to PUVA without psoralen. Trials so far good results. Cons - More research needed regarding long term results and safety issues. Expense of lasers may limit availability.Depigmentation bymonobenzene ether of hydroquinone (Topical): Used to lighten unaffected areas. Permanent. Leaves skin very light sensitive. Con- Temporary redness and swelling, skin may become dry and itchy. (Care needed not to transfer to others by skin on skin transfer for first two hours).Photochemotherapy (Oral Psoralen plus UVA) PUVA - treated in a doctors office or by using natural sunlight in a very limited dose. Must use sunscreen. Not for use in young children. Temporary side effects are burns, hyperpigmentation, nausea & vomiting, hair growth (abnormal). Cons - increase risk of skin cancer and cataracts. - Sunscreen and UV protective eye glass lenses will reduce risks.Trials and alternatives:Autologous melanocyte transplant. Using a sample of your skin, scientists can grow melanocytes then transplant the new growth onto areas that lack pigment. (This is still experimental and not widely available)Piperine a substance found in black pepper - in a lab trial (on mice) it has been found to be effective in repigmentaion, especially when used with UV light. There is a side effect of temporary redness and peeling.Ginko has been found effective in stopping the discoloration for people who have slow spreading and in one small trial some people had repigmentation. This has not yet been an authorized treatment and should be used only with proper supervision and your doctor's prior knowledge, due to possible drug interaction.
When was VLSI Technology created?
VLSI Technology was created in 1979.
When did VLSI Technology end?
VLSI Technology ended in 1999.
What are applications of vlsi?
sum of the applications of VLSI are chip like microcontroller,microprocessor,mobile etc
What does Vlsi era mean?
VLSI Era:- Very Large Scale Integration Era
What is mask-masking?
Masking is Softwear
What is vlsi based on hardware or software?
to say frankly it is still a confusion thing for me to decide vlsi is either hardware or software,but according to my opinion vlsi is both hardware and software.
What are the difference between VLSI and embedded design?
how to make a chip ---- vlsi how to use a chip ---- embedded systems
Is vlsi design a theory or derivation subject?
VLSI is combined of both theory and derivation with more diagrams
Jntu vlsi design btech previous question papers?
i want previous vlsi question papers
How you Developments in the field of vlsi?
there are a number of directionsa person can take in vlsi,and they are all closely related to each other.
Introduction to algorithms for VLSI design automation?
If you are looking for an introductory text on algorithms for VLSI design automation, I recommend: Sabih H. Gerez, Algorithms for VLSI Design Automation, John Wiley and Sons, Chichester, (1999).
What transistor is used in VLSI?
MOSFET
