| Feedback control of sub-atmospheric chemical vapor deposition processes -> Monitor Keywords |
|
|
 
Feedback control of sub-atmospheric chemical vapor deposition processesRelated Patent Categories: Coating Apparatus, Control Means Responsive To A Randomly Occurring Sensed Condition, Condition Of Coated MaterialFeedback control of sub-atmospheric chemical vapor deposition processes description/claimsThe Patent Description & Claims data below is from USPTO Patent Application 20070169694, Feedback control of sub-atmospheric chemical vapor deposition processes. Brief Patent Description - Full Patent Description - Patent Application Claims
RELATED APPLICATIONS [0001] This application claims priority under 35 U.S.C. .sctn. 119(e) from provisional application Ser. No. 60/298,878 filed Jun. 19, 2001, which is incorporated by reference. [0002] This application claims priority under 35 U.S.C. .sctn. 119(e) from provisional application Ser. No. 60/349,576 filed Oct. 29, 2001, which is incorporated by reference. [0003] This application claims priority under 35 U.S.C. .sctn. 119(e) from provisional application Ser. No. 60/366,698, filed Mar. 21, 2002, which is incorporated by reference. [0004] This application is a divisional application of and claims priority from co-pending application Ser. No. 10/174,377, filed on Jun. 18, 2002 and entitled "Feedback Control of Plasma-Enhanced Chemical Vapor Deposition Process," which is related to co-pending application filed on even date herewith and entitled "Feedback Control of Plasma-Enhanced Chemical Vapor Deposition Process," which is incorporated by reference. FIELD OF THE INVENTION [0005] The present invention generally relates to the process control of thin film deposition using sub-atmospheric chemical vapor deposition (SACVD) and more particularly to a method, medium and apparatus for providing feedback control of the SACVD deposition process. BACKGROUND OF THE INVENTION [0006] Sub-atmospheric chemical vapor deposition is used in semiconductor manufacturing to deposit thin films on substrates, for example, to deposit a silicon dioxide film on a silicon wafer. One use of sub-atmospheric CVD is in the deposition of pre-metal dielectrics (PMD). Sub-atmospheric CVD has a longer processing time than other forms of chemical vapor deposition, however, it has a much greater capability to fill trenches that are etched into wafers with very small dimensions. In these and other processes, the deposited film properties, i.e., film thickness, chemical homogeneity, and optical and mechanical properties, are important to the final device properties. [0007] In most applications, a layer is deposited over existing features on a device. The excess coating is removed, or the variation in the coating is reduced in a subsequent chemical-mechanical deposition (CMP) step. The deposited film may also have features that are created on the film using a lithography process, followed by an etch process. Thin film deposition is an inherently complex process, thereby making it hard to simultaneously control film characteristics, such as optical and electrical properties, stresses in the film, etc., while maintaining uniform film thickness. Thin film deposition processes typically "drift" over time, causing the deposited film to deviate significantly from target values. Specifically, sub-atmospheric chemical vapor deposition introduces both radial and azimuthal thickness non-uniformity, both within and among wafers. While film thickness non-uniformity can be addressed in subsequent processing steps, the greater the deposition-induced non-uniformity, the more difficult it is to achieve within-wafer thickness uniformity in subsequent steps. [0008] As microelectronics device feature sizes continue to shrink, it is necessary to have tighter controls in fabrication to maintain high yields. The semiconductor industry has developed run-to-run control of the various processing steps in a semiconductor fabrication process in order to reduce over process output variation from target. In run-to-run control, a product recipe with respect to a particular process is modified between machine runs so as to minimize process drift, shift, and variability. Post-process measurements are made periodically and are used along with empirical process models and drift compensation techniques to suggest new equipment settings for the next run. The development of feedback control has been largely empirical, based upon experimentally observed correlations between input and output measurements. [0009] There has been some investigation into feedback control of plasma etch and deposition processes, both experimental and theoretical. Implementation of process control in these operations has been limited due to unavailability of suitable integrated metrology tools, limited process understanding and non-automated operational practices. Improvements in advanced process control and reduction of run-to-run variability in a sub-atmospheric chemical vapor deposition process are thus desired. SUMMARY OF THE INVENTION [0010] The present invention relates to a method, apparatus and medium for process control of sub-atmospheric chemical vapor deposition of a film onto a surface of a substrate, for example, a semiconductor wafer, in order to provide predetermined desirable film properties and improve wafer-to-wafer and within-wafer uniformity of film properties. The present invention uses a model (which can be implemented as a single model or multiple models) of the film deposition process to predict film deposition rate, film thickness uniformity and/or other film properties across the wafer surface. Deviations from the predicted outcome are used to update the model and set new deposition recipe parameters, which feed back into the process to enhance process results. [0011] The use of multiple wafer regions in the deposition model that defines the deposited film (as contemplated by one or more embodiments of the present invention) provides greater control over the cross-film thickness. Furthermore, the methods, apparatus and mediums of the present invention (in one or more embodiments thereof) provide a model that distinguishes between depositions in different deposition chambers of the tool and between deposition parameters that are independently or commonly controlled for each chamber, thereby providing a better approximation of the tool behavior of each chamber. The methods, apparatus and mediums of the present invention (in one or more embodiments thereof also provide a model that defines the relationship between the deposition model variables and film properties other than film thickness, allowing control of the chemical, optical and/or material properties of the thin film. In addition, the methods, apparatus and mediums of the present invention (in one or more embodiments thereof) provide models that better approximate tool behavior by accounting for effects such as tool idle time, the effect of earlier-processed wafers on the current wafer, or the reliability of a value for a measured film quality. These and other aspects of the present invention allow for better estimation of tool behavior and the prediction of optimal deposition recipes for achieving a target output, thus overcoming deficiencies of the conventional technology. [0012] In one aspect of the present invention, a method of film deposition in a sub-atmospheric chemical vapor deposition (CVD) process includes: [0013] a) providing a model for sub-atmospheric CVD deposition of a film that identifies one or more film properties of the film and at least one deposition model variable that correlates with the one or more film properties; [0014] b) depositing a film onto a wafer using a first deposition recipe comprising at least one deposition recipe parameter that corresponds to the at least one deposition variable; [0015] c) measuring a film property of at least one of said one or more film properties for the deposited film of step (b); [0016] d) calculating an updated deposition model based upon the measured film property of step (c) and the model of step (a); and [0017] e) calculating an updated deposition recipe based upon the updated model of step (d) to maintain a target film property. [0018] By "deposition recipe" it is meant a set of process characteristics or parameters used to deposit a film in a deposition process. One or more of the recipe parameters are used or varied to control or influence the outcome of the deposition process. A recipe parameter corresponds or maps to a deposition model variable when it is a value selected for the deposition variable. [0019] In one or more embodiments of the present invention, the step of providing a model includes: [0020] (f) depositing a film in a sub-atmospheric CVD process on at least one wafer in a deposition step using a deposition recipe comprising at least one deposition recipe parameter that corresponds to a deposition model variable; Continue reading about Feedback control of sub-atmospheric chemical vapor deposition processes... Full patent description for Feedback control of sub-atmospheric chemical vapor deposition processes Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Feedback control of sub-atmospheric chemical vapor deposition processes patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Feedback control of sub-atmospheric chemical vapor deposition processes or other areas of interest. ### Previous Patent Application: Curtain coater with laterally adjustable edge splitting Next Patent Application: Process and device for coating strips Industry Class: Coating apparatus ### FreshPatents.com Support Thank you for viewing the Feedback control of sub-atmospheric chemical vapor deposition processes patent info. IP-related news and info Results in 0.15707 seconds Other interesting Feshpatents.com categories: Medical: Surgery , Surgery(2) , Surgery(3) , Drug , Drug(2) , Prosthesis , Dentistry 174 |
 * Protect your Inventions * US Patent Office filing 
PATENT INFO |
|
