Subtractive microfabrication

Anisotropic etching is a subtractive microfabrication technique that aims to preferentially remove a material in specific directions to obtain intricate and often flat shapes. Wet techniques exploit the crystalline properties of a stmcture... 

Microfabrication has emerged from microelectronics manufacturing and is using its proven processes and process sequences. Additionally, specific methods have been developed to fabricate mechanical, electrical, optical, or sensor structures, which are characteristics of microfabrication. In order to stay within the scope of this book, only top-down methods, that is, the manufacture of smaller structures with higher functionality from larger structures by the use of subtractive methods, will be discussed. Bottom-up methods, which create larger structures by ordered arrangement of small units (molecules, nanoparticles), are still in their infancy and mainly employed for biosensors. 

An alternative microfabrication technique is based on replication moulding. An elastomer is patterned by curing on a micromechanical mold. This technique is termed soft lithography , and is used to make blazed grating optics, stamps for chemical patterning and microfluidics devices. Soft fithography is essentially a subtractive method. 

Microfabrication techniques can be classified as follows (1) property modification, (2) patterning, (3) subtractive processes and (4) additive processes and packaging [10],... 

Figure 10.8 The decomposition of microfabrication procedure to three primary steps, that is, addition, multiplication, and subtraction of thin sohd film...

In mechanical manufacturing, components can be produced either by means of additive or subtractive processing. Microfabrication follows the... 

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