# US 7,103,484 B1 · Non-contact methods for measuring electrical thickness and determining nitrogen content of insulating films > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 7,103,484 B1 - Document ID: US7103484B1 - Status: Granted - Kind: B1 - Application number: 10/698,222 - Filed: 2003-10-31 - Granted: 2006-09-05 - Earliest claimed: 2003-10-31 - Assignees: KLA-Tencor Technologies Corporation - Inventors: Jianou Shi; Steve Yifeng Cui; Shiyou Pei; Zhiwei (Steve) Xu; Haiyong (Howard) Wang - Web page: https://patentgrep.com/patent/US7103484B1 ## CPC - G01N 27/205: {in insulating materials} - H10P 74/207: {Electrical properties, e.g. testing or measuring of resistance, deep levels or capacitance-voltage characteristics} - G01R 31/305: using electron beams {(investigating or analysing materials by measuring photoelectric effect G01N23/227)} - G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q) - H10P: GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10 - G01R: MEASURING ELECTRIC VARIABLES; MEASURING MAGNETIC VARIABLES (indicating correct tuning of resonant circuits H03J3/12) ## Abstract Non-contact methods for determining a parameter of an insulating film are provided. One method includes measuring at least two surface voltages of the insulating film. The surface voltages are measured after different charge depositions. Measuring the surface voltages is performed in two or more sequences. The method also includes determining individual parameters for the two or more sequences from the surface voltages and the charge depositions. In addition, the method includes determining the parameter of the insulating film as an average of the individual parameters. The parameter is substantially independent of leakage in the insulating film. Another method includes determining a characteristic of nitrogen in an insulating film using two parameters of the insulating film selected from equivalent oxide thickness, optical thickness, and a measure of leakage through the insulating film. The characteristic may be a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film. ## Claims ### Claim 1 A non-contact method for determining a parameter of an insulating film formed on a substrate, comprising: measuring at least two surface voltages of the insulating film, wherein the surface voltages are measured after different charge depositions on the insulating film, and wherein said measuring is performed in two or more sequences; determining individual parameters for the two or more sequences from the at least two surface voltages and the different charge depositions; and determining the parameter of the insulating film as an average of the individual parameters. ### Claim 2 (depends on 1) The method of claim 1, wherein the average is a weighted average. ### Claim 3 (depends on 1) The method of claim 1, wherein the insulating film is a leaky insulating film. ### Claim 4 (depends on 1) The method of claim 1, wherein the insulating film is a nitridated insulating film. ### Claim 5 (depends on 1) The method of claim 1, wherein a first of the two or more sequences is a reverse of a second of the two or more sequences. ### Claim 6 (depends on 1) The method of claim 1, wherein the parameter is equivalent oxide thickness. ### Claim 7 (depends on 1) The method of claim 1, wherein the parameter is substantially independent of leakage in the insulating film. ### Claim 8 (depends on 1) The method of claim 1, wherein a time delay between the different charge depositions and said measuring is kept at a minimum such that the at least two surface voltages do not decrease substantially between the different charge depositions and said measuring due to leakage in the insulating film. ### Claim 9 (depends on 1) The method of claim 1, wherein said measuring is performed in a minimum amount of time such that the at least two surface voltages do not decrease substantially during said measuring due to leakage in the insulating film. ### Claim 10 (depends on 1) The method of claim 1, wherein the different charge depositions comprise depositing a charge on the insulating film, and wherein the charge comprises a positive charge, a negative charge, or some combination of a positive and a negative charge. ### Claim 11 (depends on 1) The method of claim 1, wherein the different charge depositions are substantially uniform across an area on which the different charge depositions are performed. ### Claim 12 (depends on 1) The method of claim 1, wherein the parameter is equivalent oxide thickness, the method further comprising measuring an optical thickness of the insulating film and determining a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film using the equivalent oxide thickness and the optical thickness. ### Claim 13 (depends on 1) The method of claim 1, wherein the parameter is equivalent oxide thickness, the method further comprising determining a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film using the equivalent oxide thickness and a measure of leakage through the insulating film. ### Claim 14 (depends on 1) The method of claim 1, further comprising altering a parameter of a process tool in response to the parameter of the insulating film using a feedback control technique or a feedforward control technique. ### Claim 15 A computer-implemented method, comprising determining a characteristic of nitrogen in an insulating film using two parameters of the insulating film selected from the group consisting of equivalent oxide thickness, optical thickness, and a measure of leakage through the insulating film, wherein the characteristic comprises a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film. ### Claim 16 (depends on 15) The method of claim 15, wherein the equivalent oxide thickness is substantially independent of the leakage in the insulating film. ### Claim 17 (depends on 15) The method of claim 15, wherein the insulating film is a leaky insulating film. ### Claim 18 (depends on 15) The method of claim 15, wherein the insulating film is formed on a wafer using decoupled plasma nitridation. ### Claim 19 (depends on 15) The method of claim 15, further comprising altering a parameter of a process tool in response to the characteristic using a feedback control technique or a feedforward control technique. ### Claim 20 A computer-implemented method, comprising determining a characteristic of an insulating film using two parameters of the insulating film selected from the group consisting of equivalent oxide thickness, optical thickness, and a measure of leakage through the insulating film, wherein the characteristic comprises a dose of a component in the insulating film, a percentage of the component in the insulating film, or a presence of the component in the insulating film. ### Claim 21 A computer-implemented method, comprising determining at least one composition parameter and physical thickness of an insulating film using a model and two or more parameters of the insulating film as input to the model, wherein the two or more parameters are functions of the at least one composition parameter or the physical thickness, and wherein at least one of the two or more parameters is from a non-contact electrical measurement. ### Claim 22 (depends on 21) The method of claim 21, wherein the at least one composition parameter comprises a nitrogen dose, a nitrogen percentage, or a presence of nitrogen in the insulating film. ### Claim 23 (depends on 21) The method of claim 21, wherein the two or more parameters comprise equivalent oxide thickness, optical thickness, a thickness measurement from tunneling electron microscopy, X-ray photoelectron spectroscopy, scanning capacitance microscopy, scanning force microscopy, energy dispersive X-ray spectroscopy, electron stimulated X-ray, X-ray diffraction, or X-ray reflectance, data from charge vs. voltage, current vs. voltage, or capacitance vs. voltage measurements, or information about a process used to form the insulating film. ### Claim 24 (depends on 21) The method of claim 21, wherein the at least one composition parameter comprises a characteristic of nitrogen or oxygen in the insulating film, and wherein the insulating film is formed on a wafer using decoupled plasma nitridation or a high-k process. ### Claim 25 (depends on 21) The method of claim 21, further comprising monitoring or controlling at least one parameter of a process tool using the at least one composition parameter or the physical thickness.