Glossary

3D Integration is divided into two main categories: 3D packaging and 3D interconnect. 3D packaging is used to describe components stacked on a wafer-level packaging strata without being connected using Through-Silicon Vias (TSVs). 3D packaging is comprised of technologies such as SOC (System-on-Chip) and other processes for which the connection is normally based on wire bonding. 3D interconnect on the other hand includes components joined by TSVs. This refers to vertical vias through the massive silicon which, as a general rule, is heavily thinned.

This term describes modern technologies to “package” microchips in their housing. All microchip contacts must be guided individually to the outside of the housing to ensure a connection to the printed circuit board. Advanced packaging involves packaging processes that generally employ methods previously used only in the frontend manufacturing of microchips themselves, such as lithography and photoresist technologies.

This term is used to describe the second (rear) link in the microchip production chain. The backend process begins once the wafer has passed through all frontend process steps in the manufacture of the microchip itself. In this process, microchips are tested on the wafer and, if required, prepared for bonding. The wafers are then sawed into individual microchips that are packaged in their housing. For cost reasons, backend process work is primarily done in Asia, where semiconductor manufacturers have backend facilities of their own or allow foundries to handle testing and packaging.

Attaching two or more components or wafers to each other by means of various chemical and physical effects. Adhesive bonding, for example, uses adhesives (usually epoxy resins or photoresists) to attach two components. Fusion or direct bonding directly links two wafers that are initially only connected by the weak atomic forces (van der Waals forces) of water molecules in the borderline layer. By subsequently applying heat, the water molecules are broken down, and the oxygen atoms released combine with the wafer’s silicon atoms to form the covalent bond silicon oxide. This is a very strong, non-soluble bonding of the two wafers.

A metallic (solder, gold, or similar) three-dimensional contact on a chip. In simple terms, it is described as a ball of solder on a single microchip contact.

General term used for semiconductor components. In electronics, a chip or microchip is understood to mean an integrated circuit embedded in housing. From the outside, all one generally sees is the black housing and the connection point that links the chip and printed circuit board (by wire or flip chip bonding). The piece of silicon in the housing is frequently also referred to as the chip or microchip.

A Coater is a special machine for the production of semiconductors. It disperses photosensitive resist to the wafer by way of rotational power.

Semiconductor composed of several elements, such as gallium arsenide, indium phosphide, silicon germanium, etc. Advantages over simple semiconductors include: speed, high temperature compatibility, and lower energy consumption.

Die, IC (integrated circuit), and chip are terms often used synonymously. Integrated circuits are known as dies until the point at which they are integrated into housing. Wafers are referred to as dies as long as they are going through the individual process steps. The term “chips” is only used after the dies are isolated and packaged.

An advanced bonding technique between chip and housing that makes higher clock frequencies possible in signal transmission. The active side of the chip is face down and, therefore, has to be “flipped” before assembly.

A chip factory where microchips are manufactured to a circuit design that is specified by the customer. Making goods to order in this way, the foundry operators have no chip design or product sales/marketing costs and can, therefore, focus their R&D resources entirely on the process technology. The globally leading foundries are located in Taiwan and Singapore.

Frontend processes are the production steps carried out on the wafer as a whole. This is where the chip itself is made. Backend processes in which chips are tested on the wafer follow. There, the wafer is cut into individual chips that are then inserted into housing.

An integrated circuit (IC) consists of electronic components such as transistors, resistors, and capacitors that are integrated on a tiny microchip. Today, tens of millions of this type of cells are housed in circuits on a single chip. This high integration density has led to a high degree of chip performance.

Light-emitting diode. LEDs are semiconductor components that can generate light. They emit a very bright light, yet, at the same time, consume very little energy. Moreover, their life span is over ten times that of a conventional light bulb.

The electrical circuits of ICs are created by structuring individual strata on a silicon wafer in a type of layer structure. To create very small structures in the individual strata, the wafer is coated with a light-sensitive material (photo-resist) and then exposed using a mask. The structures on the mask are, thus, superimposed on the wafer by means of casting a shadow. Where the mask blocks the light, the photoresist on the wafer is not exposed. Where it is transparent, light falls onto the wafer and the photoresist is exposed. During development after exposure, the exposed photoresist areas are cleared above the strata and can be accessed by the following process step. Nowadays, typical structure sizes for frontend lithography applications are between 32nm (0.032 micrometers) and 0.6 micro-meters. In the backend, structure sizes ranging from several microns to tens of microns are generated by photolithography to create, for example, bumps for flip chip bonding.

A plate of glass or quartz glass on which the patterns needed to manufacture an IC are mapped. These patterns consist of transparent and opaque areas that correspond in size and shape to the circuits required.

Mask Aligners align a glass mask to a wafer (covered with photosensitive material previously spun or sprayed on by a coater) with sub-micrometer accuracy. The glass mask is patterned with the structures which need to be transferred onto the wafer. These structures will then build electrical circuits, grooves, and bridges – all the various things that the chip needs in order to function. The pattern is transferred onto the wafer by means of exposure not unsimilar to a photographic procedure.

Microelectromechanical systems (MEMS) is the term used primarily in North America for microsystems technology (MST), a term more common in Europe. Semiconductor production technologies and processes are used to manufacture mechanical and other non-electrical elements. MEMS products are used, for example, in the automobile industry, telecommunications, optoelectronics, and medical technology.

This term is defined differently by region. In Europe, it means the entire miniaturization of precision mechanics component structures of less than 1 mm. In the United States and Asia, in contrast, microsystems technology or the more frequently used microelectromechanical systems (MEMS) means the use of semiconductor electronics technologies to produce the smallest of sensors or even complex systems such as a complete chemical or biological analysis unit. MEMS components include, for example, the silicon acceleration sensor that is used to activate an airbag or an inkjet printer cartridge nozzle.

A light-sensitive material that is first applied as a layer to the wafer and then exposed through a mask using ultraviolet light. In exposed areas, the ultraviolet light brings about chemical changes. These areas are dissolved from the layer during development, leaving a relief-like structure in the photoresist coating. This process is highly similar to photography.

A monocrystalline material of which the electrical resistance can be changed by implanting foreign atoms into its crystal grid. Silicon is the most important and also the most frequently used semiconductor element. ICs made of silicon are also often called semiconductors.

A component used to record and convert measurements such as temperature, pressure, and acceleration. These measurements are converted into electrical signals and relayed to a signal evaluation unit.

A material with the structure of a crystal lattice with semiconducting properties. Semiconducting means that the material can be used as a conductor or non-conductor depending on the inclusion of certain foreign atoms. In the semiconductor industry, the most common base material used is silicon in monocrystalline disk form.

Coaters spread a photosensitive resist on the wafer. The SUSS MicroTec Spin Coater specializes in thick photo resists, which are applied to the wafers. The Spray Coater sprays a substrate and can thus also coat three-dimensional structures evenly.

The Substrate Bonder connects two or more substrates (primarily wafers) aligned to one another in an extremely precise manner. This is done using soldering, adhesion, or another physical-chemical process. Many MEMS components require this processing step, as it is the only way to ensure that airbags, tire pressure sensors, GPS sensors, ink-jet printers, etc. work.

Individual chip components are stacked on top of one another and joined with this technology. This shortens the path of the data stream between the individual chip components and allows for significantly less capacity loss. As such, Through-Silicon Vias contribute to lowering the overall size of chips combined with a simultaneous rise in performance.

Slices of the purest silicon, for example, or compound semiconductors (gallium arsenide, indium phosphide, etc.) on which chips are produced. Over the past ten years, their diameter has increased from 150mm to 200mm and today to even 300mm. Twice as many chips fit onto the surface area of the latest 300mm wafers than onto a 200mm wafer, cutting production costs by approximately 30%.

A common contact process that connects chips with housing via metal wires.