Chemical Vapor Deposition wafer thickness

For epitaxial silicon wafers, product design focuses on optimizing the geometry of the plasma-enhanced, chemical-vapor-deposition (PECVD) reactor. To increase productivity, and maintain acceptable thickness uniformity, on the order of 5%, a simple optimization strategy locates a design that completes the deposition in 62 s. Then, for a standard manufacturing process, the economics are driven by the wafer costs, which are provided by a vendor at 206/wafer. At a sales price of 260/epitaxial wafer, the investor s rate of return is 18.3% and the return on investment is 25.3%. 

The steam reformer is a serpentine channel with a channel width of 1000 fim and depth of 230 fim (Figure 15). Four reformers were fabricated per single 100 mm silicon wafer polished on both sides. In the procedure employed to fabricate the reactors, plasma enhanced chemical vapor deposition (PECVD) was used to deposit silicon nitride, an etch stop for a silicon wet etch later in the process, on both sides of the wafer. Next, the desired pattern was transferred to the back of the wafer using photolithography, and the silicon nitride was plasma etched. Potassium hydroxide was then used to etch the exposed silicon to the desired depth. Copper, approximately 33 nm thick, which was used as the reforming catalyst, was then deposited by sputter deposition. The reactor inlet was made by etching a 1 mm hole into the end... 

Figure 15 records an example of this relationship between incoming thickness variation and post-CMP thickness variation. The incoming thickness variation is due to the fact that the TEOS film was deposited in two different plasma-enhanced chemical vapor deposition (PECVD) chambers, which are not calibrated identically [13]. As can be seen in Fig. 15, the pre-CMP wafer-to-wafer thickness variation pattern has been perfectly preserved after CMP. 

On a metal surface, silicide layers can be formed by two methods. In the first, Si atoms are vapor deposited by heating either a well degassed silicon wafer or a silicon rod to near its melting point. In the second method the metal is heated in 10 to 50 mTorr of silane for a desired length of time, usually about 10 to 60 s at a desired temperature, usually about 300 to 700°C. The first method is better suited for studying very early stages of silicide formation, the second more convenient for growing thick layers of silicides. Chemical vapor deposition or laser enhanced chemical vapor deposition may probably be used also, but have not yet been explored. 

Adem of Advanced Micro Devices, Inc. was granted a patent on the use of Raman spectroscopy to monitor the thickness, crystal grain size, and crystal orientation of polysilicon or other films as they are deposited on semiconductor wafers via low-pressure chemical vapor deposition (CVD).89 The spectra are acquired with a non-contact probe through a suitably transparent window in the loading door. A feedback scheme is discussed. When the thickness has achieved the targeted value, the deposition is stopped. If the crystal grain size or orientation is deemed unsuitable, the deposition temperature is adjusted accordingly. 

The wafers were coated with silicon dioxide (400 nm thickness) and silicon nitride by low pressure chemical vapor deposition (LPCVD) alternately. The chips were fabricated by photolithography and etching. The catalyst (for the application Pt) was introduced as a wire (150 pm thickness), which was heated resistively for igniting the reaction. The ignition of the reaction occurred at 100 °C and complete conversion was achieved at a stochiometric ratio of the reacting species generating a thermal power of 72 W (Figure 2.28). 

Franz et al. [93] developed a palladium membrane micro reactor for hydrogen separation based on MEMS technology, which incorporated integrated devices for heating and temperature measurement. The reactor consisted of two channels separated by the membrane, which was composed of three layers. Two of them, which were made of silicon nitride introduced by low-pressure chemical vapor deposition (0.3 pm thick) and silicon oxide by temperature treatment (0.2 pm thick), served as perforated supports for the palladium membrane. Both layers were deposited on a silicon wafer and subsequently removed from one side completely... 

Commercial n-type 6H-SiC wafers with a concentration of uncompensated donors Nd - Na = 3x lO cm were used as substrates. These substrates were covered with a thin epitaxial n-GaN buffer layer grown by hybrid vapor phase epitaxy (HVPE). This buffer layer had a thickness of 0.2 pm and a donor concentration of Nd-Na = (2-3)xl0 cm . On top. Mg doped / -type AlGaN epitaxial layers with thickness of 0.8 pm and an Al content of 12 at.% were also grown by HVPE with an acceptor concentration of Na-Nd = (5-8)xl0 cm. Then, Ga doped n-ZnO epitaxial layers were deposited using chemical vapor deposition (CVD) with a thickness of 0.8 pm and a donor concentration ofNd - Na = 7xl0 cm. The growth process was stimulated by a discharge plasma, that allowed to reduce the substrate temperature by up to 400 °C and thus improve the structural quality of the ZnO layers. ... 

In chemical vapor deposition (CVD), a semiconducting or insulating solid material is formed in a reaction between a gaseous species and a species adsorbed on the surface of silicon wafers (disks about 10 cm in diameter and 1 mm thick). The coated wafers are subjected to further processing to produce the microelectronic chips in computers and most other electronic devices in use today. 

P3-23b Chemical vapor deposition (CVD) is a process used in the microelectronics industry to deposit thin films of constant thickness on silicon wafers. This process is of particular importance in the mamifactuiing of very iai-ge scale integrated circuits. One of the common coatings is Si3N4, which is produced according to the reaction... 

Boron-doped diamond (BDD) thin films were synthesized at CSEM (Neuchatel, Switzerland) by the hot filament chemical vapor deposition technique (HF CVD) on p-type, low-resistivity (l-3mQcm), single-crystal, silicon wafers (Siltronix). The temperature of the filament was between 2440 and 2560 °C and that of the substrate was monitored at 830 °C. The reactive gas was a mixture of 1% methane in hydrogen, containing trimethylboron as a boron source (1-3 ppm, with respect to H2). The reaction chamber was supplied with the gas mixture at a flow rate of 51 min giving a growth rate of 0.24 pm h for the diamond layer. The obtained diamond film has a thickness of about 1 pm ( 10%) and a resistivity of 15mQcm ( 30%). This HF CVD process produces columnar, random textured, polycrystalline films [9]. 

Chemical Vapor Deposition in boat reactors is discussed and modeled. The equations and parameters which affect wafer thickness and shape are derived and analyzed. This material is taken directly from the second edition of this book. See Professional Reference Shelf R12.4. 

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