TW504784B - Using refractory metal silicidation phase transition temperature points to control and/or calibrate RTP low temperature operation - Google Patents

Abstract

A method for controlling and/or calibrating rapid thermal process systems is described. One or more wafers comprising a silicon semiconductor substrate having a refractory metal layer thereon are silicided in a RTP system at different temperatures. Sheet resistance uniformity of the wafer is measured thereby detecting silicidation phase transition temperature points at the highest uniformity points. The temperature points are used to calibrate or to reset the RTP system. A plurality of wafers comprising a silicon semiconductor substrate having a refractory metal layer thereon can be silicided in each of a plurality of rapid thermal process systems. Sheet resistance uniformity of each of the wafers is measured thereby detecting silicidation phase transition temperature points by highest sheet resistance uniformity for each of the RTP systems. The temperature points are used to match temperatures for each of the RTP systems. The temperature point depend upon the type of refractory metal used and can range from about 200 to 800 DEG C.

Description

Chuan 4784

[Background of the Invention] (1) Field of the Invention The present invention relates to the manufacture of integrated circuit components, and in particular, it is used to control the temperature of a quasi-disc during R τ P low temperature operation and the monitoring during the manufacture of integrated circuits. Method. (2) Explanation of learned skills

In the manufacture of integrated circuits, the rapid heating process (RTP) has been implemented in the heating process. For the reproducible results in the RTP process, accurate control of time and temperature is necessary. This is particularly difficult to control. Rapid heating annealing process (RTA) system, and the temperature between 200 to 80 (Tc, between low-temperature system systems, usually, a pyrometer sensor is used for RTP / m degree control 'sensor can The actual wafer temperature is detected by the optical signal emitted from the wafer. This optical signal is quite low compared to high-temperature radiation.

T is the wafer temperature. For a lower temperature, the signal emitted from the wafer is smaller. If a thermocouple is used to detect the temperature, a lower temperature will also result in a lower voltage signal of the thermocouple. In the fab or between fabs, the same or different ^ RTP used in the same process and the same program temperature setting, in the current module correction system of the school, the same plant, Tian Gengxun a Hard cock is male? t The absolute temperature of each cock can be different from each hardware cockroach 'To match the system, this difference must be minimized. Temperature sensitivity curve (showing resistance versus temperature) has been used in system design

Page 9 504784 V. Description of the invention (2) However, wafer conditions and substrate composition play a major role in the output chip resistance of the RTP process. These factors are not included in the temperature sensitivity curve. Methods for accurate temperature control and temperature matching between systems. U.S. Patent No. 6,132,081 (Han) discloses a method for determining the rtp temperature to form a fragmented chimney. The temperature is set to a temperature after the sheet resistance and / or non-uniformity are constant, that is, the temperature It is not sensitive. This method is also used to calibrate a light sensor. This method cannot meet a temperature trend to a higher part, and cannot be used for daily system matching. US Patent No. 6, 136, 613 (Lin et al.) Teaches a method for cyclically monitoring wafers, which includes annealing and measuring sheet resistance. U.S. Patent No. 5, 33, 676 (Lambert et al.) Shows a method for calibrating furnace tube temperature using a temperature probe. U.S. Patent No. 5,326, 1 70 (Moslehi et al.) Shows a calibration wafer with a solid component melting point, such as a calibration temperature point. [Summary of the Invention] One of the main objects of the present invention is to provide a method for effective temperature control and extremely manufacturability in a rapid heating process (RTP) system. Another object of the present invention is to provide a method for controlling RTp operation. Another method of the present invention. The purpose is to provide a method for calibrating RTP temperature and low operation, and to provide a control and / or calibration method.

504784 V. Description of the invention (3) Evenness change. Xi μ ί Another bright point is to provide a method that is compatible with the rtp system. It is obtained by monitoring the uniformity spikes of the chip resistance and the temperature change of the uniformity.又一 Another object of the present invention is to provide a method for controlling and / or low-temperature operation of RTP, which is obtained by monitoring the temperature change of the film = uniformity change.峄 』大大 峄 和 均 Another object of the present invention is a method for monitoring temperature in Aω ^^.糸 lies in the supply-species of the above-mentioned purpose made in the heating process system 'is to obtain a calibrated RTP low-temperature operation RTP Λ Λ The wafer system is composed of a material conductor substrate Λ; ρ / Λ' the Shixi semiconductor substrate It has a refractory metal layer ;;, "The uniformity of the peak chip resistance of the wafer coming out, therefore, the average peak resistance of the peak chip resistance is detected, and the surface temperature is converted to another temperature setting and / or control RTP The system. The conversion of the 'overflow conversion system is used for heavy operations: ΐ 颍 ΐ 颍 copy! For the purpose of the purpose, it is obtained-a kind of controlled flap low temperature RTP f * * Φ The system is a wafer composed of a silicon semiconductor substrate on which' measured ' The first point of temperature of the wafer is to convert the silicon layer to silicon. The first temperature point is 22: The second wafer composed of the bond test board is in the RTp system, and it is a kind of silicon semiconductor based system in K ^ P. It is silicified in the system. The silicon semiconductor has a different refractory metal layer on it. The uniformity of the Λ circle and the large t resistance is measured. Therefore, the second phase transition of the silicidation process is detected.

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The first and second temperature points of the / JBL degree station are used for temperature calibration. Station, w According to the purpose of the present invention, a system is obtained—a method that conforms to a variety of RTP systems. Γ st Γ Lai, a plurality of wafers composed of a semiconductor substrate and a plurality of rapid heating process systems are siliconized. The semiconductor-based system has a refractory metal layer on it, and measures the uniformity of the peaks of each wafer.! 1, It is said that the phase transition temperature of the petrification process of each RTP system is measured. ^ ^ The temperature point of the uniformity is the temperature used in each M? System. According to the novel method of the present invention, a novel method of warming a silicon semiconducting rapid heating process system is covered with silicon and a type of refractory metal layer. The peak chip resistance of each wafer is equal to the siliconized phase transition temperature point HP system. 'Due to the control of the formation of a plurality of wafers of the low-body substrate of the RTP system, the silicon semiconductor substrate system has no' temperature can be as low as 200 ° C-the sample is low, the uniformity is measured 'Therefore, each wafer is detected These kinds of temperature points can be used for control. [Pattern number comparison description] Wafer 14 refractory metal layer 16 cap layer 18 metal silicon layer 31 line segment 3 3 line segment 34

f p.12

V. Description of the invention (5) 35 temperature 41 curve 42 curve 43 curve [Explanation of the preferred embodiment] Accurate temperature control is i: heavy for the rapid heating process (RTp) system; Second, the temperature change in the RTP system will 'Most wafer phase destruction' is critical for any temperature change detected early

So that wafer damage can be ruled out. The process of the present invention can be used to set the temperature of the starting weight of the system and maintain the temperature control during the use of the system. Furthermore, the process of the present day can meet the temperature between the systems. For example, a 5t target temperature for a titanium silicide treatment: the temperature trend will greatly affect the narrow sheet resistance and cause serious yield loss. Low temperature RTP applications (less than 750) include refractory metal silicidation, low temperature annealing, and Heating 'temperature control is particularly important in these operations.

The refractory metal self-aligned with the silicified phase transfer shows a significant increase, and the sheet resistance uniformity of the material decreases. The highest uniformity of the refractory metal will occur at the temperature point indicating the silicified phase transition. For most refractory In the case of metal silicidation, the transition temperature will be in the low temperature region, and new materials and low temperatures will become an industrial trend. The second point of the phase transition of Shixi Chemical treatment can be used to detect the difference in RTP low temperature control and / or system. The temperature setpoint matches the system. Once you accurately find the temperature set point for each different refractory metal, this

Page 13 504784-V. Description of the invention (6) __ = The set point can be used to calibrate the RTP system. The present invention has a better effect than the calibration method using the technique. An error occurred in or in the thermocouple. / In daily conditions, the quasi-conditional temperature set point can be used to control the temperature of an RTP system. The average resistance of small resistors will be different from that of different refractory gold ^, and the uniformity of peaks will be large. One or lower temperature *, which indicates a temperature trend, calibration: square: two :: Turn off the system to prevent damage and recalibrate the system. : ,,, The current temperature control based on chip resistance measurement is not sensitive. 3: = the relationship between wafer differences, and the change in chip resistance will be due to the difference in wafers. Different surface conditions: Degree: and resistance value, these factors will affect the sheet resistance as well as the temperature of the furnace tube, and will not affect the uniformity of the sheet resistance. The change in the uniformity of the sheet resistance is only affected by the conversion temperature. Therefore, the present invention The manufacturing process (based on chip resistors) will be more accurate than conventional techniques. … The process of the present invention can also be used to meet the temperature between the systems. By performing the same kind of wafer and measuring the resistance in the same system in the same process, a temperature difference can be detected, as long as this is found Difference or compensation, the system can be adjusted to conform to the same process. ▲ The method of the present invention uses the observation of the uniformity of the sheet resistance to detect that the temperature is only reduced. The uniformity of the sheet resistance is very sensitive to temperature because of the phase conversion of the refractory metal silicidation treatment. Most of the sensitive temperatures can be obtained from one or more petrochemical treatment methods. 1 ^ 1 Page 14 504784 V. Description of the invention The second series uses different refractory metal thicknesses and / or cover layers and detects temperature points. ' These changes in film thickness or cap layer may allow more Hau temperature points to be confirmed, and more temperature points may provide a more accurate RTp system. For example, in order to determine the phase transition temperature, a refractory metal layer (such as cobalt trinickel, titanium, tungsten, molybdenum, button, platinum, or other similar) is deposited on a wafer to achieve a temperature less than 丨A thickness of 0 0 Angstroms to 丨 00 Angstroms, a capping layer (such as titanium, titanium nitride, or other similar materials) can be sunk on the refractory metal layer to achieve a thickness of less than 100 angstroms to 50 (50 angstroms). FIG. 1 illustrates a wafer 10 (for example), a refractory metal layer 14 has been deposited on a substrate, and a capping layer 16 covers the refractory metal layer. Well, now, wafers are used at temperatures between 200 and 800. (: The rapid thermal annealing (RTA) between is annealed, depending on the type of wafer used. Annealing will cause the metal layer to react with the silicon semiconductor substrate to form a metal silicon layer. After the RTA, several The sheet resistance on the surface is measured using a four-point furnace tube or other device. The sheet resistance uniformity is ⑽ ^ σ / χ) χ ι〇〇 where σ is the standard error of all measured points, and χ is all measurements. The average of the points.

〇 Figure 3 is a graph illustrating the temperature sensitivity of Ti / Co / Si. These wafers already have a layer of cobalt 130 angstroms thick and a 200 angstrom titanium cap layer. During the RTp process, the temperature has reached four temperature points. The sheet resistance and the uniformity of the sheet resistance were measured. Segment 31 shows the resistance value that increases the temperature, and segment 33 shows the increase temperature ^ uniformity value. Because the phase transition occurs, the phase transition temperature can be confirmed from the highest uniformity line, that is, In this case, the temperature 35 represents a phase inversion

V. Description of the invention (8) —------------ Change the resistance uniformity (U%) of the chip resistor to indicate the programmed temperature set point. Show one, w # 3 in the graph of any change in temperature 35 at the program temperature set point. *: Conversion and if the conversion is required to shut down the system temperature, any temperature conversion will result in the measurement. A huge change in chip resistance uniformity that can be easily detected. Table 1 shows some set temperatures that determine the three wafers. Table 1 The highest u% of membrane types after RTP

Ni / Si Ti / Co / Si Ti / Si 200 ° C ～ 675 〇C ～ 730 〇C

: Once the above temperature is accurately found, these multiple points can be used for calibration. FIG. 4 illustrates a baseline uniformity curve 41 for a particular wafer type. The template 1 is a temperature setting determined by the highest uniformity point. In the process of the present invention, a single RTp system is monitored. Template 2 or Template 3 (curves 42 or 43 respectively), this represents the temperature required for a temperature conversion and reset system. In an RTp-compliant system, if system 1 has the highest u% on template 1, and system 2 has the highest u% on template 2 or template 3, system 2 needs to be adjusted.

FIG. 5 illustrates the baseline uniformity curve 51 of a first type of refractory wafer. This set point is a template 4 and the baseline uniformity curve 52 of a second type of refractory wafer has a set point of template 5. Different types of refractory wafers have different phase transition temperatures. Two or more types of wafers can be used to calibrate the RTP temperature sensor. In this case, two temperature templates 4 and 5 will be used to calibrate the RTP temperature sensor. , Calibration temperature and 200 ° C —

Page 16 504784 V. Description of the invention (9) Sample low and 800 ° C — sample high, for example, the Ni S ix phase transition temperature is close to 200 ° C, TiSix is 73 (TC and WSix can be Higher. The process of the present invention uses the uniformity of the peak chip resistance to determine the phase transition temperature setpoints for low temperature applications in fast heating processes. These temperature setpoints can be used to calibrate the RTP system to control the RTP system and conform to the RTP system. temperature.

Although the present invention has been particularly shown and described with reference to the preferred embodiments thereof, various changes in form and detail may be made without departing from the spirit and scope of the present invention, which can be done by those skilled in the art. understand.

Page 17 504784 Brief description of the drawings In the drawings that form the content of this description, the following are shown: Figures 1 and 2 illustrate cross sections of a wafer used in a preferred embodiment of the present invention Illustration. Figure 3 is a graph illustrating the relationship between the temperature of a wafer, chip resistance, and uniformity. Figure 4 is a diagram illustrating the relationship between temperature, chip resistance and uniformity of different RTP systems.

Figure 5 is a graph that does not explain the relationship between the temperature of the two wafers, chip resistance, and uniformity.

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Claims (1)

504784 VI. Scope of patent application 1 type of school 2 4 5 67 There is a subordinate layer in the fast measurement of the resistance. Use the same as the application to select the group system. If the application layer is splashed, if the cover layer is applied, if the application is self-contained, the application process is the same as the application process. If the application process is 8, such as the method of temperature point precision / rapid heating process system, including: Siliconized in the rapid heating process system A wafer including a silicon semiconductor substrate having a refractory gold on it; the chip resistance uniformity of the wafer, and thus detecting the siliconized phase transition temperature at the highest wafer uniformity Point; and temperature point 'to calibrate the rapid heating process system. The method described in item 1 of the patent fc, wherein the refractory metal is from the method described in item 1 of the group of patents containing titanium, titanium, nickel, tungsten, molybdenum, tantalum, and platinum, wherein the refractory metal ore is deposited To a thickness between 100 Angstroms and 1,000 Angstroms. The method described in item 1 of the patent scope further includes depositing a cap on the refractory metal layer. The method described in item 4, wherein the capping layer is selected from the group consisting of titanium and titanium nitride, and wherein the capping layer has a thickness of less than 100 angstroms to 500 angstroms. The method described in item 1 of the patent scope, wherein the rapid heating system is selected from the group containing silicidation treatment and low temperature annealing. The method described in item 1 of the patent scope, wherein the rapid heating system is a low temperature process, Its temperature is between 200 and 800 t = the method described in item 1 still includes the use of this to standardize the rapid heating system to meet another rapid Side I Page 19 504784 VI. Scope of patent application Heating system. 9 The number of wafers described in item 1 of the scope of the patent application, in which the refractory metal is still siliconized. 4 people have multiple thick tangs, and some of the multiple wafers include a stack of + / 、 The middle layer, where it is said that a plurality of petrified chemical processing phases are measured m = The temperature points are used for calibrating the rapid addition process system 10 A reset one rapid addition process system you Φ ^ ^… The method to reach an indefinite temperature point 'includes: siliconizing a first wafer in the rapid heating process, the first crystal including a silicon semiconductor substrate, and having a refractory metal layer on the rapid heating process; During the process, a second wafer is silicided, and the second wafer is packaged with a silicon semiconductor substrate and has the same refractory metal layer thereon; /, the sheet resistance uniformity of the first wafer and the second wafer is measured , And therefore the debt detects the temperature change point of the silicidation treatment at the highest uniformity of the chip resistance; compares the highest uniformity temperature point to the set temperature point to detect a temperature change; and 'use the temperature change To reset the quick Heating process system. 11. The method according to item 10 of the scope of patent application, wherein the refractory metal layer is selected from the group consisting of cobalt, titanium, nickel, tungsten, molybdenum, tantalum, and platinum. 12 · The method according to item 10 of the scope of patent application, wherein the rich metal Scope of patent application 13. The layer is sputter-deposited to a method between 100 angstroms and 1,000 angstroms, as described in item 10 of the scope of patent application, with a cover layer of 5 thicknesses covering the refractory metal layer. on. With deposition 1 4 · As described in item 13 of the scope of the patent application, the hair towel _ from the group containing titanium and titanium nitride 'and wherein the cover layer is a base product of less than 1 0 0 Angstroms to 500 Angstroms in thickness. … 15 • The method as described in item 10 of the scope of patent application, wherein the rapid heating process system is selected from the group consisting of silicidation, low temperature annealing, and heating ^. 16 · The method as described in item 10 of the scope of patent application, wherein the rapid heating process system is a low temperature process, the temperature of which is between 200 and 800 ° C. 17 · As in the scope of patent application 10 The method described in the item further includes silicifying the plurality of first and second wafers, wherein the refractory metal layer has a plurality of thicknesses, and some of the plurality of wafers further include a capping layer covering the refractory metal layer. In the above, a plurality of first and second silicidation phase transition temperature points are detected, and a plurality of the first and second temperature points are used to detect the second temperature change. 1 8 · A method that meets a plurality of rapid heating process systems, including: silicifying a wafer in each of the plurality of rapid heating process systems, the wafer system including a silicon semiconductor substrate, and having a refractory The metal layer is on it; the uniformity of the sheet resistance of the mother wafer is measured, and therefore each Page 21 504784 VI. Application for patent The siliconized phase transition temperature point of the rapid heating process system with the highest uniformity of the sheet resistance; and the temperature point is used to meet the temperature of each rapid process system. [19] The method according to item 18 of the scope of patent application, wherein the refractory metal layer is selected from the group consisting of cobalt, titanium, nickel, tungsten, rhenium, buttons, and platinum. 20. The method as described in claim 18, wherein the refractory metal layer is sputter deposited to a thickness between 100 angstroms and 100 angstroms. 2 1 · The method according to item 18 of the scope of patent application, further comprising depositing a capping layer on the refractory metal layer. 2 2 · The method according to item 21 of the scope of patent application, wherein the capping layer is selected from the group consisting of titanium and titanium nitride, and wherein the capping layer is sputter-deposited to less than 100 angstroms To a thickness of 500 angstroms. 23. The method according to item 18 of the scope of patent application, wherein the rapid heating system is selected from the group consisting of petrochemical treatment, low temperature annealing, and heating. 24. The method according to item 18 of the scope of patent application, wherein the rapid heating process system is a low temperature process with a temperature between 2000 and 800. 25. According to the item 18 of scope of patent application The method further includes silicifying a plurality of first and second wafers, wherein the refractory metal layer has a plurality of thicknesses, and some of the plurality of wafers further include a capping layer covering the refractory metal layer, wherein A plurality of first and second silicidation phase transition temperature points are detected, and the plurality of first and second temperature points are used to detect the second temperature change. Page 22