Chemistry: electrical and wave energy – Processes and products – Coating – forming or etching by sputtering
Patent
1995-10-16
1997-08-26
Weisstuch, Aaron
Chemistry: electrical and wave energy
Processes and products
Coating, forming or etching by sputtering
20419217, 20419225, C23C 1434
Patent
active
056606940
DESCRIPTION:
BRIEF SUMMARY
TECHNICAL FIELD
The present invention relates to a film forming apparatus. In greater detail, the present invention relates to a film forming method for simultaneously conducting chemical vapor deposition and sputtering and forming a film, and to a film forming apparatus.
BACKGROUND ART
The coating of thin films on the surfaces of parts or elements, and the provision of predetermined functions, is often conducted in an extremely wide range of fields, such as electric and electronic parts, tools, machine parts, and the like. Semiconductor devices such as integrated circuits and the like are representative thereof; such devices are produced by repeated film formation and minute working, so that film forming apparatuses play an extremely important role in the manufacturing processes thereof.
Furthermore, in integrated circuits, in concert with the miniaturization of the devices, higher performance and quality are required, and for this reason, there has been a strong demand for a film forming method which is capable of forming, according to design, the impurity distribution in deposition films comprising the devices. For example, in the case of a bipolar transistor, the high speed characteristics of LSI, such as high speed operating elements, memory, digital/analog converters, and the like, or of elements which are extremely widely employed as discrete elements, are determined by how fast electrons pass through the base layer, so that a structure in which the base layer is made thinner and the passage distance is reduced, a gradient is created in the impurity concentration in the thin base layer and an internal electric field is formed, and which is capable of accelerating the electrons and exhibits a sharp impurity density change at the interface, for example, an impurity density distribution having a gradient such as that shown in FIG. 9, is effective in increasing element performance.
Conventional film forming apparatuses can be broadly divided into two groups based on the operating principle of the film forming method. That is to say, such apparatuses can be classified into film forming apparatuses which employ physical methods such as vapor deposition, sputtering, and the like, and film forming apparatuses which employ chemical reactions of film forming raw material gases, or the so-called chemical vapor deposition (CVD) methods. Such apparatuses have superior operability, simplicity of maintenance, high operation rates, and the stability of the quality is also superior, so that such apparatuses are widely employed; however, it is difficult to change the impurity density of the deposition film described above or the component ratio, and furthermore, it is difficult to form sharp changes in impurity density.
For example, when the impurity density of the deposition film or the component ratio is changed by means of vapor deposition or sputtering, it is necessary to change the impurity density or component ratio of the vapor deposition materials or the target materials themselves in correspondence with the impurity density of the deposited film or the component ratio. Furthermore, when aluminum silicide used as the wiring material of the semiconductor integrated circuit is formed by means of sputtering, it is necessary that the target have the precisely appropriate combination of aluminum and silicon. In addition, when deposition films having differing component ratios are formed, it is necessary to change the target each time to one which is appropriate for the composition of the deposition film. However, the impurity density or component ratio in the direction of depth of films deposited using standard film forming apparatuses is as shown in FIG. 8(a), and is constant in the direction of depth.
When attempts are made to control the impurity density or component ratio in the direction of depth as, for example, in FIG. 8(b), as a continuous function of the direction of depth (in the Figure, a straight-line relationship), such control is extremely difficult using vapor deposition or sputtering methods, s
REFERENCES:
patent: 4496450 (1985-01-01), Hitotsuyanagi et al.
patent: 4824546 (1989-04-01), Ohmi
patent: 4874494 (1989-10-01), Ohmi
Miyashita Kazuhisa
Ohmi Tadahiro
Shibata Tadashi
Uetake Hiroaki
Ohmi Tadahiro
Weisstuch Aaron
LandOfFree
Film forming method does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Film forming method, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Film forming method will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-1985449