Why use quartz tank for semiconductor wet etch process?

In semiconductor wet etching process, experts suggest that you choose an etching system that uses quartz tank (or is made from quartz materials). And there are compelling reasons why this is so. Well, aside from it is made from the second most abundant mineral that can be found in the Earth's continental crust, some practical reasons why it is recommended (and why should you use quartz tank) are the following:

• Durability - considered to be harder than granite and most metals, it makes sense that quartz are durable and so anything that is made from quartz is considered durable as well. This is one of the reasons why quartz tank is popular in the industry.
• Non-reactivity to a variety of chemistries - quartz is also one of the materials that do not react to chemistries (e.g. it does not react with acid) and thus, the substrate that is processed inside it safe from contamination.
• High purity - quartz provides high purity standard so there is nothing to worry about  this problem. This is very important most especially when processing semiconductors wherein high purity is absolutely necessary.

Aside from quartz tanks, some quartz products that can be used in processing works are the following:

• Quartz boats - also known as substrate carriers; designed to accommodate wafers of 4", 6", 8", and 12" in diameter; they can come in various designs or sizes and manufacturers can also design according to your specifications.
• Quartz chambers - designed to accommodate plasmas that can reach extremely high temperatures but need high purity and visual verification; they are ideal because they are high resistant to heat.
• Quartz drains - are generally placed on the side or at the bottom part of quartz tanks.; they can be used to recirculate chemistry or for tank evacuation.
• Quartz aspirators - these are also known as filter pumps; the tool is used to produce a vacuum by means of the Venturi effect; this is used in high temperature applications.
• Quartz boat adapters - can reduce cost in wafer processing; can also help for increased production throughput.

Computer chassis anodizing - a practical way to protect your system units

Anodizing, an electrolytic passivation process, is aimed at increasing the thickness of the natural oxide layer on the surface of metal parts. This process is also being applied to computer chassis (also known as computer casing) as this is a practical way to protect a system unit, particularly the components inside it.

Here are some practical benefits of anodizing computer chassis:

• Makes the computer casing sturdy and therefore can not be easily deformed when a force is exerted on it; provides more strength to the casing and therefore can hold the components in their places.
• Makes the metal sheet more resistant to corrosion and therefore can prolong the system unit's life span; anodizing protects the metal sheet from air moisture and other external constraints that can potentially damage the components inside.
• Makes the metal sheet with less scars and more resistant to wearing, which is common during fabrication and surface dirt cleaning

Anodizing advantages over other metal sheet processes:

• The process is generally less expensive
• Anodizing, as opposed to other form of coating, cannot peel-off since the coating itself is part of the metal.
• Anodizing's translucent property gives a metal sheet a deeper, richer metallic appearance, which is not only aesthetically advantageous but opens the possibility of computerized color matching with quantitative, objective color data.
• Anodizing is environment friendly; anodizing service providers, therefore, are indeed taking a bold step for environmental rehabilitation/protection campaign leading to a sustainable development. 

Silicon Wafer Foundry Service Providers - Important Contribution to Semiconductor Industry

Silicon wafer foundry service providers have been useful to the semiconductor industry and the sectors it serves. The advanced technology it offers, particularly with the advent of fabless business model, provides the affordability advantage, which is essential to maintaining minimal production costs of the foundry processes. Through foundry service providers' process capabilities, the production of semiconductor components such as MEMS have been efficient ajd cost-effective in the recent years.

Foundry service providers have a number of process capabilities, including:

• Lithography - also known as photolithography is a process that puts specific patterns on silicon wafers; the patterns are written on the substrates using a light sensitive polymer called photoresist. This process is essential to the production of semiconductor components that connect millions of transistors of a circuit.
• Etching - in simpler terms, it is a process of making prints on the surface of the substrate or wafer. Several wafer foundry companies have a broad range of wet etching capability for 300mm and smaller diameters, for a broad range of dielectrics and metal films. They can also process non-standard sized substrates.
• Wafer reclaim and recovery - this service is a practical way of extending the life of the wafers; wafer foundry service providers have the capacity to mechanically re-polish wafers to remove film, surface scratches, and residual patters. While there is a certain limit on the number of times a wafer may be reclaimed, still this procedure is a cost effective solution to customers.
• Thin films (dielectrics) - includes thermal oxide and LPCVD processes; foundry companies use equipment like custom furnaces to carry out Thermal Oxide process.
• KISS Polishing - a process used by wafer foundry service companies to remove minor surface scratches or defect on the substrates. This service includes visual inspection of wafers for chips and cracks. 

 There are still a lot of process capabilities inside a foundry service facility - thanks to the people behind these innovations. True indeed that they are a big help to the semiconductor industry and the sectors it serves.

Sapphire Etching - Dry vs Wet Process

There are two popular etching processes being used to produce pattered sapphire substrate - the dry and wet etching. It is imperative to know the differences between the two so that a manufacturing company is able to determine which between the two is better. To help you with that, I have prepared below some points of comparison:

Dry etching

• considered to be the most common method to etch sapphire substrate productiona very slow process with a low throughput rate; 
• a standard 2-inch wafer can consume between 30 and 60 minutes to etch. 
it does not scale effectively. As a wafer size increases, throughput of a dry etcher falls as fewer wafers fit inside the vacuum chamber. And because of that,  more expensive plasma etching tools are needed to achieve the same throughput as was achieved on smaller wafers.
• as an estimate, dry etching rates range between 50nm to 200nm per minute is attainable.
• it creates bright, efficient LEDs but does so slowly and with limited throughput

Wet etching

• is known to provide dual advantages of being extremely fast and a lot cheaper than dry etching
• it is very scalable but produces LEDs that are not quite as effective or efficient as dry etching.
• it provides a considerable cost saving than the dry etching
• polishing touch-up work is performed on hte wafers in order to increase light extraction efficiency

Some equipment used in etching process:

• The Accubath Xe-Series -- an etching bath equipment from Imtec Acculine, was designed with Sapphire etching in mind but we know there are other processes that will benefit from the increased chemical reactivity that higher temperatures provide (300°C). Processes that were previously thought to be too slow due to temperature limitations may now be practical because of innovations like this.
• Hitachi High-tech Silicon Etch System -- this equipment is used in dry etching based on an ECR(*1) plasma source, it is capable of generating a stable high density plasma at a very low pressure.
• CDE-80N Chemical Dry Etching Equipment -- Performs chemical dry etching of thin film on a semiconductor wafer in gaseous state (dry). Damage-free etching process through perfect separation of the etching unit and plasma generating unit enables wide use in the damage removal process.

Each of the etching processes discussed above has its own advantages and disadvantages. But, just like any other processes, select the one you think can improve your bottom-line -- profit.    

Why Failure Analysis Is Critical To Manufacturing Process?

Failure analysis, a process that relies on collecting failed components for subsequent examination of the cause or causes of failure, is considered as one critical discipline in many branches of manufacturing process because it can effectively help in the following:

• Refinement of an existing product - many products found in the market today can still be refined with the help of failure analysis; this is with the help of several procedures including collecting data of their failed components, which are brought to a laboratory for analysis in order to determine the cause and act accordingly.
• Development of new products - in many cases, the discovery of a certain cause of failure cannot just be useful for the refinement of the existing one but, of equal importance, can lead to the development of new/other products, which can be useful to both manufacturers and consumers as well.
• Cost reductions - physical and electrical failure analysis, which helps in determining the cause of failure, reduces costs as manufacturing companies can use better materials and avoid unnecessary spending and wasting, which therefore can help reduce materials and operational costs and improves profits.

There are two popular categories under failure analysis and these are the following:

• Electrical failure analysis - some examples of electrical failure analysis work can be done during dielectric breakdown, component failure, arc tracking/conductive path tracking, poor quality solder joints, floating neutrals and high voltage transients, oxidation and corrosion of electrical connections, and contamination of circuit boards. Mechanisms used as part of electrical failure analysis include Analytical Probe Station, Curve-Trace (Manual & Automated); Emission Microscopy (Near Infrared); Florescent Micro-Thermal Imaging with Lock-In; Laser Stimulation Microscopy.
• Physical failure analysis - this becomes increasingly important for process optimization for situations like when there is a continued shrinking of materials used in a certain manufacturing process. In cases like the one specified, a particular manufacturing facility can do the analysis (or hire a third party to do it) such as 3-D X-ray Tomography, C-scanning acoustic Microscopy, De-Capsulation, Deprocessing, FIB-SEM Cross Sectioning, Mechanical Cross-Sectioning, Real-time X-ray - among other physical failure analysis procedures.

More and more companies in the manufacturing sector have recognized the importance of failure analysis and have incorporated this procedure in their own system for product refinement and development of new ones.

Finding The Right Classic Car Restoration Shop To Bring Your Dream Car Back To Its Beauty And Power

Repair and restoration works are some of the most challenging tasks a classic car owner could have. For one, because of the unique nature of this job (not all car repair shops offer classic car repair services); second, finding a restoration shop that caters your needs is pretty expensive - that is, if you are not wise enough to choose the best classic car repair in town.

With the aim of helping you find a good, reputable classic car restoration shop, I have prepared some tips below - some insights you might find useful:

• Credentials - this does not only mean the papers or documentations but a list of projects a particular classic car restoration shop has accomplished during the course of time or period it has been in business. Aside from examining its records, asking its previous customers or persons who experienced working with a particular shop can be a great help in examining its credentials. The bottom line is, as is the case of most industries, no matter how good or bad a classic car restoration company in terms of selling itself, it is always the credentials that speaks more convincingly.
• The length of time in service - most of the time (if not all the time) those companies who are more capable of providing good quality service are those who have been in business for quite some time. That is also true when it comes to classic car restoration shops. Generally, the longer the time a company has been is business means that it has gained the necessary experience to become a better service provider.
• The manpower - another factor that you should consider as you choose your service company. A particular service provider might be good in a number of ways; however, if it has a limited manpower to carry out its service, it could suffer a major drawback that can compromise the quality of its service as a whole. See to it that your prospective company has the ideal number of workforce to do the classic car restoration jobs.
• The logistics - you should also examine whether or not a classic car restoration shop is advantageous in your part, logistically. You should also find out where your service provider does the job - is it at its own shop? or does a particular service provider offer restoration service at home? The bottom-line is that the logistics consideration is one area that you should consider as this can reduce your overall service expenses. 

A classic car restoration shop can bring your dream car back to its beauty and power without spending too much of your money. It is just a matter of finding the most qualified ones.

Some Etching Processes for MEMS

Microelectromechanical Systems or more commonly known as MEMS is a technology designed for very small devices. It is made up of components between 1 to 100 micrometers in size; it is being used in numerous applications such as in electronics, biotechnology, communication, and medicine.

MEMS production/fabrication is carried out by a number of processes, which include deposition, parttering, and etching. However, in this content, we are to focus on the etching processes for MEMS.

There are numerous processes involved in MEMS etching but they can be categorized in two broad categories - dry and wet etching.

Dry etching - the material is dissolved using reactive ions or a vapor phase etchant; one advantage of this process is that it is capable of defining small feature size (<100 nm). It has several disadvantages as well, including: high cost, low throughput, poor selectivity, hard to implement, and the potential for radiation damage.

Sample of dry etching

• Xenon fluoride etching - primarily utilized for releasing metal and dielectric structures by undercutting silicon; this dry vapor phase isotropic etch process was first used in 1995.
• Plasma etching - a dry etching process, which process involves generation of reactive species, diffusion of these species, and then adsorption.

Wet etching - the material is dissolved through immersion in a chemical solution inside a wet bench. It has a number of advantages, including: low cost, easy to implement, high etching rate, and good selectivity for most materials. However, it has several disadvantages as well such as the inadequacy for defining feature size < 1 micrometer.

Sample of wet etching 

• Isotropic etching - known as the non-directional removal of material from a substrate in a chemical process with the help of a substance/mixture called an etchant.
• Hydrofluoric acid etching - a process that uses an aqueous etchant for silicon dioxide

There are quite a number of processes involved in etching - each has advantages and disadvantages. One thing is certain, however - etching is an important part of micro fabrication that essential to the production of devices needed in the industry and society.