Semiconductor device manufacturing: process – Having organic semiconductive component
Reexamination Certificate
2002-07-18
2004-07-20
Seidleck, James J. (Department: 1711)
Semiconductor device manufacturing: process
Having organic semiconductive component
C427S255280, C427S255250, C427S430100
Reexamination Certificate
active
06764873
ABSTRACT:
BACKGROUND OF THE DISCLOSURE
1. Field of the Invention
The present invention is directed to a semiconductor wafer which includes a low dielectric constant thermosetting polymer layer and a method of making same. More specifically, the present invention is directed to a semiconductor wafer which includes a polymeric film layer which is a product of a reaction mixture which includes one or more curable monomers and liquid or supercritical carbon dioxide and a method of making same.
2. Background of the Prior Art
The continuing increase in the speed of integrated circuits disposed on semiconductor wafers and the like is the result of the development of dramatically decreased size integrated circuits on semiconductor wafers. This decreased size of integrated circuits results in thinner spaces between individual devices, elements and topographical features thereon. This decreased thickness between devices, elements and topographical features has put increased demand upon the electrical resistance and capacitance of insulating layers disposed between these devices, elements and topographical features of such integrated circuits. A special concern of this decreased thickness is the increasing number of integrated circuit failures caused by shorts and the like. This development emphasizes the need in the art for new dielectric constant polymeric films useful in insulating new and smaller integrated circuits on semiconductor wafers.
That the art recognizes this need is established by recent developments in this art. For example, Peters,
Semiconductor Inter.,
63-74 (September, 1998) provides a general background article describing the development of low dielectric constant materials for use in integrated circuits. This article evidences the concern in the art for the need of improved low dielectric constant interlevel insulators.
U.S. Pat. Nos. 5,965,679 and 6,288,188 disclose polyphenylene oligomers and polymers useful as dielectric resins in microelectronic fabrication. These polymers, which may be thermosetting, involve the reaction product of a biscyclopentadienone and a polyfunctional acetylene.
The utilization of liquid and supercritical carbon dioxide in integrated circuit processing is well known in the art. Many applications, utilizing liquid or supercritical carbon dioxide in the processing of integrated circuits disposed on semiconductor wafers are known in the art. However, these processes are typically directed to the removal of debris and the like that result from processing of integrated circuits. For example, U.S. Pat. No. 5,908,510 is directed to the removal of residue from an etched precision surface of a device, such as a semiconductor wafer or the like, by exposing the precision surface to liquid or supercritical carbon dioxide.
Copending U.S. patent application Ser. No. 09/893,104 is directed to a dielectric material and a process of forming the same in which an already formed polymer is contacted with liquid or supercritical carbon dioxide. That disclosure, although a significant advance in the art, is distinguished from a product produced from one or more curable monomers. In the invention of the copending application film quality is controlled during spin-on of the dielectric material. Therefore, porosity control is a strong function of the diffusion parameter of liquid or supercritical carbon dioxide and, optionally, the solvent. Simply stated, physical properties of the film formed in accordance with the invention of the copending application cannot be controlled during polymeric film spin-on and thus are dependent upon the diffusion parameter of the carbon dioxide in the polymeric film.
It is furthermore emphasized that in a preferred embodiment of the copending application, wherein a co-solvent is employed, the solvent acts as a porogen. It is more desirable to employ an optional solvent as a plasticizer, to enhance flow and planarizing capabilities. In this manner a more uniform film, having minimal thickness deviations across the circuit assembly, could be obtained.
BRIEF SUMMARY OF THE INVENTION
A semiconductor wafer, which includes a new low dielectric constant polymeric film and a method for making that wafer which includes a new low dielectric constant polymeric film has now been discovered. The new polymer is one of a class of low dielectric constant polymers recently developed, which dielectric constant is further reduced by introducing pores therein. However, unlike prior art porous polymers, the pores are formed concurrently with the polymerization of the polymer. These pores fill with air, a material having a dielectric constant of 1, further reducing the dielectric constant of the already low dielectric constant in-situ formed porous thermosetting resin.
In accordance with the present invention a semiconductor wafer including a low dielectric constant polymeric film is provided. The polymeric film layer is provided by disposing a composition which comprises one or more monomers, curable upon the application of a radiation source or thermal energy, a solvent for the monomer or monomers, liquid or supercritical carbon dioxide and, optionally, a co-solvent on a semiconductor wafer. The composition of curable monomer(s), liquid or supercritical carbon dioxide and, optionally, a co-solvent is intimately mixed and disposed on the wafer at a temperature in the range of between about 30° C. and about 50° C. and a pressure of at least about 73 atmosphere. The temperature of the composition is thereupon incrementally raised to at least about 450° C. followed by incremental temperature reduction to ambient temperature. The pressure, which is maintained at at least about 73 atmospheres during initial temperature elevation, is reduced when a temperature of at least about 310° C., more preferably, between about 310° C. and about 400° C., is reached. The exact temperature is a function of the desired pore size distribution of the product film. When this temperature is reached, pressure is reduced incrementally to atmospheric pressure.
In further accordance with the present invention a process is provided for the preparation of a semiconductor wafer which includes a low dielectric constant polymeric film. This process includes the steps of combining at least one curable monomer and liquid or supercritical carbon dioxide at a temperature in the range of between about 30° C. and about 50° C. and at a pressure of at least about 73 atmospheres. The temperature of the thus formed composition is thereupon incrementally raised to at least about 450° C. and then incrementally reduced to ambient temperature. The pressure is maintained at at least about 73 atmospheres until the temperature, which is incrementally advanced, reaches at least about 310° C. The pressure is thereupon incrementally reduced to atmospheric pressure.
DETAILED DESCRIPTION
A new semiconductor wafer, which includes a low dielectric constant polymeric film, is produced in which that film is prepared by combining at least one curable monomer, a solvent therefor, liquid or supercritical carbon dioxide and, optionally, a co-solvent under thermodynamic conditions consistent with the maintenance of the liquid or supercritical carbon dioxide in that state. Thus, at least one curable monomer is combined with liquid or supercritical carbon dioxide at a temperature in the range of between about 30° C. and about 50° C. and a pressure of at least about 73 atmospheres. More preferably, the one or more curable monomers and liquid or supercritical carbon dioxide are combined at a temperature in the range of between about 35° C. and about 40° C. and a pressure in the range of between about 75 atmospheres and about 80 atmospheres. The one or more curable monomers and the liquid or supercritical carbon dioxide are intimately mixed, under these thermodynamic conditions, until a uniform product is obtained. In the case where a co-solvent is used, the aforementioned treatment extends to the inclusion of the co-solvent.
The thus formed, intimately mixed reaction mixture is thereupon subjected to incremental increasing t
Hichri Habib
Malone Kelly
Martin Arthur
Pepper Margaret
Scully Scott Murphy & Presser
Seidleck James J.
Tran Thao
LandOfFree
Semiconductor wafer including a low dielectric constant... does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Semiconductor wafer including a low dielectric constant..., we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Semiconductor wafer including a low dielectric constant... will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-3256923