Methods of forming dielectric materials

Semiconductor device manufacturing: process – Making field effect device having pair of active regions... – Having insulated gate

Reexamination Certificate

Rate now

  [ 0.00 ] – not rated yet Voters 0   Comments 0

Details

C438S398000, C438S773000, C438S746000, C438S787000, C438S964000

Reexamination Certificate

active

06562684

ABSTRACT:

TECHNICAL FIELD
The invention pertains to methods of forming dielectric materials, and methods of forming capacitors. The invention also pertains to capacitor constructions.
BACKGROUND OF THE INVENTION
It is frequently desired to form dielectric mater Is during semiconductor device fabrication. For instance, capacitor constructions comprise dielectric material separating a pair of capacitor electrodes. Suitable dielectric materials for capacitor constructions include silicon dioxide and silicon nitride, with an exemplary dielectric material comprising a stack of silicon nitride between a pair of silicon dioxide layers.
An advantage of utilizing silicon nitride in capacitor constructions is that it has a higher dielectric constant than silicon dioxide. However, a difficulty in utilizing silicon nitride can occur in attempting to get a uniform coating of silicon nitride over a capacitor electrode. For instance, a capacitor electrode can comprise conductively-doped rugged silicon (for example, conductively-doped hemispherical grain polysilicon). Such rugged silicon has a rough surface texture, and is utilized because the rough surface texture enables more conductive surface area to be provided over a particular footprint than would be provided with a smooth-surfaced structure. A difficulty can occur in attempting to form silicon nitride over the roughened surface structure of rugged silicon. Specifically, silicon nitride is typically provided by chemical-vapor deposition (such as, for example, low pressure chemical vapor deposition utilizing silane and ammonia as precursors), and the nitride deposits non-conformally on the roughed surface of the rugged silicon. Accordingly, if the nitride is provided as a thin layer (less than 100 Å thick), there can be pinholes extending into the nitride, and even extending through the nitride to expose portions of the underlying rugged silicon surface.
Among the methods which have been developed to compensate for the pinhole problems are methods in which silicon dioxide is formed over the layer of silicon nitride to either fill the pinholes or at least cover the pinholes with a dielectric material. The silicon dioxide can be formed by either chemical vapor deposition, or by oxidation of the silicon nitride surface.
Another method for compensating for pinhole problems is to form silicon dioxide over the rugged polysilicon prior to formation of the silicon nitride. Accordingly, a dielectric material will be beneath the silicon nitride, and any pinholes extending through the silicon nitride can be prevented from exposing the underlying conductive substrate by the intervening layer of silicon dioxide.
In typical prior art processing, both of the above-discussed silicon dioxide methodologies are utilized. In other words, a layer of silicon dioxide is formed before forming the layer of silicon nitride, and a second layer of silicon dioxide is formed after forming the layer of silicon nitride.
It would be desirable to develop methods wherein some or all of the above-discussed difficulties associated with formation of silicon nitride could be eliminated, and particularly it would be desirable to develop methods wherein one or both of the above-discussed layers of silicon dioxide could be eliminated from capacitor constructions.
SUMMARY OF THE INVENTION
In one aspect, the invention encompasses a method of forming a dielectric material. A nitrogen-comprising layer is formed on at least some of the surface of a rugged polysilicon substrate to form a first portion of a dielectric material. After the nitrogen-comprising layer is formed, at least some of the substrate is subjected to dry oxidation with one or both of NO and N
2
O to form a second portion of the dielectric material.
In another aspect, the invention encompasses a method of forming a capacitor. A layer of rugged silicon is formed over a substrate, and a nitrogen-comprising layer is formed on the layer of rugged silicon. Some of the rugged silicon is exposed through the nitrogen-comprising layer. After the nitrogen-comprising layer is formed, at least some of the exposed rugged silicon is subjected to dry oxidation conditions with one or both of NO and N
2
O. Subsequently, a conductive material layer is formed over the nitrogen-comprising layer.
In yet another aspect, the invention encompasses a capacitor structure. The structure includes a first capacitor electrode comprising a rugged polysilicon layer, a nitrogen-comprising layer on the rugged polysilicon layer, and a second capacitor electrode. The nitrogen-comprising layer is between the first and second capacitor electrodes.


REFERENCES:
patent: 4254161 (1981-03-01), Kemlage
patent: 4585516 (1986-04-01), Corn et al.
patent: 4882649 (1989-11-01), Chen et al.
patent: 4891684 (1990-01-01), Nishioka et al.
patent: 4996081 (1991-02-01), Ellul et al.
patent: 5039388 (1991-08-01), Miyashita et al.
patent: 5051794 (1991-09-01), Mori
patent: 5052339 (1991-10-01), Vakerlis et al.
patent: 5102523 (1992-04-01), Beisswenger et al.
patent: 5142438 (1992-08-01), Reinberg et al.
patent: 5147493 (1992-09-01), Nishimura et al.
patent: 5230931 (1993-07-01), Yamazaki et al.
patent: 5260236 (1993-11-01), Petro et al.
patent: 5261962 (1993-11-01), Hamamoto et al.
patent: 5272417 (1993-12-01), Ohmi
patent: 5324679 (1994-06-01), Kim et al.
patent: 5376593 (1994-12-01), Sandhu et al.
patent: 5433786 (1995-07-01), Hu et al.
patent: 5439524 (1995-08-01), Cain et al.
patent: 5468296 (1995-11-01), Patrick et al.
patent: 5498890 (1996-03-01), Kim et al.
patent: 5504029 (1996-04-01), Murata et al.
patent: 5508542 (1996-04-01), Geiss et al.
patent: 5523596 (1996-06-01), Ohi et al.
patent: 5567267 (1996-10-01), Kazama et al.
patent: 5605637 (1997-02-01), Shan et al.
patent: 5607542 (1997-03-01), Wu et al.
patent: 5656123 (1997-08-01), Salimian et al.
patent: 5661072 (1997-08-01), Jeng
patent: 5665167 (1997-09-01), Deguchi et al.
patent: 5716534 (1998-02-01), Tsuchiya et al.
patent: 5731235 (1998-03-01), Srinivasan et al.
patent: 5844771 (1998-12-01), Graettinger et al.
patent: 5851603 (1998-12-01), Tsai et al.
patent: 5863339 (1999-01-01), Usami
patent: 5865937 (1999-02-01), Shan et al.
patent: 5900103 (1999-05-01), Tomoyasu et al.
patent: 5919332 (1999-07-01), Koshiishi et al.
patent: 5942075 (1999-08-01), Nagahata et al.
patent: 5985738 (1999-11-01), Jang et al.
patent: 6001748 (1999-12-01), Tanaka et al.
patent: 6037220 (2000-03-01), Chien et al.
patent: 6048769 (2000-04-01), Chau
patent: 6051510 (2000-04-01), Fulford et al.
patent: 6063713 (2000-05-01), Doan
patent: 6093617 (2000-07-01), Su et al.
patent: 6093661 (2000-07-01), Trivedi et al.
patent: 6111744 (2000-08-01), Doan
patent: 6112697 (2000-09-01), Sharan et al.
patent: 6127221 (2000-10-01), Lin et al.
patent: 6150278 (2000-11-01), Tan et al.
patent: 6159867 (2000-12-01), Sharan et al.
patent: 6218260 (2001-04-01), Lee et al.
patent: 6227141 (2001-05-01), Sharan et al.
patent: 6235646 (2001-05-01), Sharan et al.
patent: 6486020 (2002-11-01), Thakur et al.
patent: 0 552 491 (1993-07-01), None
patent: 0 641 150 (1995-03-01), None
patent: 0 678 903 (1995-10-01), None
patent: 0 686 708 (1995-12-01), None
patent: 0 742 577 (1996-11-01), None
patent: 0 776 991 (1997-06-01), None
patent: 0 831 679 (1998-03-01), None
patent: 2 663 806 (1991-12-01), None
patent: 5-175163 (1991-12-01), None
patent: WO 89/02685 (1989-03-01), None
patent: WO 95/32315 (1995-11-01), None
patent: WO 98/32154 (1998-07-01), None
Rayner, J. et al., “Radio Frequency Matching for Helicon Plasma Sources”, J. Vac. Sci. Technol. A 14(4), Jul./Aug. 1996, pp. 2048-2055.

LandOfFree

Say what you really think

Search LandOfFree.com for the USA inventors and patents. Rate them and share your experience with other people.

Rating

Methods of forming dielectric materials does not yet have a rating. At this time, there are no reviews or comments for this patent.

If you have personal experience with Methods of forming dielectric materials, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Methods of forming dielectric materials will most certainly appreciate the feedback.

Rate now

     

Profile ID: LFUS-PAI-O-3029640

  Search
All data on this website is collected from public sources. Our data reflects the most accurate information available at the time of publication.