TW482832B - Single crystal pulling-up - Google Patents

Abstract

To provide a method by which the resonance frequency of a pendulum consisting of a pulling-up wire and a growing single crystal can be changed correspondingly to length of the growing single crystal, in single crystal pulling-up by a CZ (Czochralski) method. This method comprises growing a single crystal while changing a seed shaft resonance frequency in such a way that a plot of the seed shaft resonance frequency crosses a plot of single crystal rotation rate. More concretely, at the time of growing a part in the vicinity of the top of the single crystal, the crystal rotation rate S/R is maintained at a high level to reduce the oxygen concentration and, on the other hand, at the time of growing a part in the vicinity of the bottom of the single crystal, the crystal rotation rate is maintained at a low level to prevent the single crystal from being deformed. In the method, initially, the seed shaft resonance frequency is set to a value on a straight line segment drawn from a point of frequency (a) to a point of frequency (b), that is lower than the S/R value and, thereafter, the length of a pendulum consisting of a pulling-up wire and the growing single crystal is shorten to switch the seed shaft resonance frequency to a value on a straight line segment drawn from a point of frequency c to a point of frequency (d), that is higher than the S/R value.

Description

V. Description of the Invention (1) [Technical Field of the Invention] The method of drawing single crystals using the cz method. L 『Knowledge technology』 Early crystal silicon is generally filled with single crystal manufacturing equipment Jcz = using the cz method. Then (resolve Λ ...), soak the shaped crystals in the melt, while rotating in the seed direction or in the opposite direction, _ side pull with = British hanging steel to grow to the predetermined diameter and The length of the aa support, so that when the single crystal silicon single crystal is grown, as shown in Figure 1-1, the pull-out lead 1 G is set and hunted by the pull-up lead curling drum η and the seed crystal 15, or by The seed crystal support pendulum of the lead wire and the wire end is formed by curling a single crystal of m to ten in the lead wire to form a clock and the seed crystal 15 rotates at a rotation speed of S / R, and the lead wire 10 comes out along a vertical axis. The radius around γ is the dagger's seed 15, and the green is drawn along the vertical axis Y, and the member pulls the lead 10 to move. The pendulum has a cone of 1 ° per minute. The pendulum f = 60X1 ... x (g / I :; the two frequencies f (/ min) can be expressed by the following formula where g is the acceleration of the free-falling body. L (Eq. 1) In order to make the crystal rotation number and the Yau line 1 0 effective Length. The single-point and vibration frequencies disclosed in 63-303888 are inconsistent, and a bellows coil is provided in JP-A Zhao (Μ— Ώ from said unit may drop between the upper line Jian Governing crimped portion 'corresponds to the line speed crystal rotation crimped 482832

Up or down, and change the effective length of the lead wire, set the weight of the resonance frequency to be larger than the crystal rotation speed S / R, or set the resonance frequency number f to be smaller than the crystal rotation speed S / R, and avoid pulling the lead Of resonance. [Problems to be Solved by the Invention] In the past f years, in order to increase the efficiency of semiconductor device production and increase the yield, single crystals have progressed toward an increase in diameter or length. To cope with this tendency, The height also increases. In the single crystal growth device disclosed in the above-mentioned conventional Japanese Patent Application Laid-Open No. 63-303 88 8, when the total south degree of the clothes is changed, the number of resonance frequencies will decrease, so the crystal rotation speed will also have to decrease, causing the single crystal Deterioration of the in-plane resistance or oxygen concentration of the crystal. In addition, when the crystal rotation speed changes abruptly, the quality of the crystal is deteriorated, and furthermore, a differential discharge phenomenon is caused. When the crystal continues to rotate around the resonance frequency, the amplitude increases due to the resonance phenomenon, and many disadvantages occur. Since the resonance frequency is determined by the position and crystal length of the lead wire curling drum 1 set, it will gradually increase, so it is impossible to set an arbitrary crystal rotation speed across the number of resonance frequencies. Aiming at the above-mentioned conventional problems, the present invention focuses on the above-mentioned conventional problems. The purpose of the present invention is to provide a single crystal pulling method, which can change the resonance of the pendulum composed of the lead wire and the early crystal according to the growth of the crystal. Frequency 〇 [Method used to solve the problem] In order to achieve the above-mentioned purpose, the first feature of the single crystal pulling method according to the present invention is that in the single crystal pulling process using the CZ method, one side of the single crystal T ,,, 〇 The degree of crystal growth changes the resonance frequency of the seed axis to cross the number of crystal rotations.

With the above configuration, the seed crystal axis resonance frequency determined by the length of the center of the drum of the lead wire curling device according to the single crystal can be arbitrarily changed. Second: the long side of the center of gravity position of the crystal can resonate the seed axis. The frequency is set to 7 ^ number of crystal rotations. With this, a much lower value, one side can pull bow 丨 single s ~ crystal rotation speed is much higher or; the degree of growth of the crystal to avoid seed crystal two earning 2 'Because-the side can be approached by one side, while one side can be high speed; : = Frequency and crystal rotation speed of the single crystal in-plane resistivity or oxygen j to pull, so again, according to this; reduce. The crystal pulling method is: when the breeding = the second feature of the primer method, the single rotation speed is maintained at a high speed to reduce the ^ P ^ near the top, the crystallization spin is maintained at a low speed, hindering X, during the breeding In the vicinity of the bottom, in the method, near the top, the deformation of the single crystal is stopped. Here, the rotation speed of the crystal is low. When the bottom is grown, the resonance frequency of the seed crystal axis is set to be higher than the rotation speed of the crystal. -Inch is near time 'The seed crystal axis resonance frequency is composed of the above. ^ In the Gukou mouth stage, the seed crystal axis resonance frequency is ^ 2. Near the top of the early crystal, it is easy to make the crystal rotate at the beginning. The rotation speed is lower than that of the crystal, and the later stage is near the bottom of the crystal ^ ^^. In addition, because the single crystal grows at a high rotational speed, the seed crystal axis resonance frequency is set to be lower than that of the crystal, the in-plane resistivity of the single crystal, or the rotational speed of the two crystals is reduced. Hereby, further according to the invention 3:;: is reduced. The third feature of the single crystal pulling method or the third feature of the single pulling method is described in the second feature of the above A by the S section and the T section 482832. 5. Description of the invention (4) '------ and The moon is a single crystal. The S interval is the difference between the seed crystal axis resonance frequency and the crystal rotation speed by 2rnm η, the τ region a + τ is raised above the left by upm, and the 1 tween is in the stall that does not hinder the growth of the single crystal. The resonance frequency of the seed crystal axis and the number of crystal rotation speeds are crossed. This single crystal pulling method is composed of 3 intervals, τ intervals, and the following s intervals. In order to achieve the crystal quality, the seed crystal axis is resonance frequency. It may be said that the difference between the rotation speed of the crystal and the rotation speed of the crystal is more than 2 rpm to produce a single crystal. The T interval is that although the resonance frequency of the seed axis and the rotation speed of the crystal are crossed by 1, the degree of resonance phenomenon is intensified. Within the cultivating sun of the sun, the resonance frequency of the seed axis and the rotation speed of the crystal are crossed, and the resonance frequency of the seed axis is greatly changed. In the τ interval, once the crystal rotation speed is drastically changed, the difference between single crystals will be transformed. “Because of this, the change of the crystal rotation speed should be slow” and the switching of the resonance frequency of the seed crystal axis should be fast. [Embodiments and Examples of the Invention] Next, an embodiment of the single crystal pulling method of the present invention will be described with reference to the drawings. Fig. 1 shows a single crystal manufacturing apparatus using the single crystal pulling method of the present invention. A vacuum container 3 is provided at the upper end of the single crystal manufacturing apparatus. The vacuum container 3 includes a fixed container 3b provided above and below a carriage 14 that is raised and lowered by rotation of a bolt 13 and a fixed container 3b at a lower portion. The upper rotating container 3 a which is rotatably supported on the horizontal plane. The upper rotary container 3a is driven to rotate on a horizontal plane by a motor 2 provided on a stand 14. The upper rotary container 3a contains a lead wire curling drum 1. Furthermore, under the lower fixed container 3 b, telescopically flexible ones are connected in order.

482832 V. Description of the invention (5) Bellows 4 and pull-in palace 5b 48. The original to be filled in the crucible ": f is provided with a crucible 7 and a heater 9, which will be heated by the seed crystal support n, ', evening sun and the like ... to obtain a melt, -The seed crystal 12 that holds the holder 11 and is set at the lower end of the pull wire and soaks in the molten metal 9 at a time. In addition, the frame 14 raised by the pull-up of the lead wire 10 is formed by a straight space, and the stand 14 that is lifted and lowered by the rotation of the φφ / bolt 13 is provided for free lift. ~ The industrial valley device 3 can be within the expansion and contraction limit of the bellows 4 'Crystal growth speed V can V -V 丄 ν *-Pulling speed of the lead 10, ν table \ Apple SL bis t' Among them ^ 表 德 办 ^ Γ Pull the lead position of the curling drum 1 before the movement DP1, the movement of the coil (Λ,%). The relationship between m and the time required for the movement of the curling drum 1 can be used in the formula. 丨 Used as i: axis = the next day glaze resonance frequency Control program at the time of change. Figures 2 to 5 show the other changes of the single crystal manufacturing equipment shown in Figure 2. Figure 2 shows the state where the bellows 4 is extended to the maximum, and the state of H is soaked in the liquid. At this time The length u of the pendulum is the distance from the center of the lead wire 2 and the surface of the solution 9 to the surface of the solution 9, a specific example is 3005_. Furthermore: the telescopic range of the bellows 4 is 1 00 mm. In this state, the lead wire is pulled down The resonance frequency f (/ min) of 10 can be expressed by the following formula: f = 60 XI / 2 7Γ X (9. 8/3. 05) 1/2 = 17. i (equation 2) Figure 3 shows the bellows extension to In the maximum state, a schematic diagram of pulling a single crystal 12 with a length of 10,000 mm in the straight section. The center of gravity position G of the single crystal 12 is 500 mm below the upper end of the straight section, and the length of the pendulum L2, that is, The pull wire crimped center drum 1 to the length of the gravity center position is 22 5〇mm 6,

482832

V. Description of the invention (6) In this state, the resonance frequency number f (/ min) of the lead wire 10 can be expressed by the following formula: f = 6 0 X 1/2 7Γ X (9. 8/2. 25) 1 / 2 = 19.9, two, no (Equation 3) In short, from the time when the seed crystals are immersed in the melt to the food at the place where the seed crystals are μ μN, the resonance frequency of the seed crystal axis The number f varies between 17 · i and 19 9. Furthermore, FIG. 4 shows a state where the length of the bellows is compressed to a minimum, and the state where the seed crystals are immersed in the melt. The length L 3 of this pendulum is the distance from the center of the lead wire curling drum 1 to the surface of the melt 9. Since the bellows has a telescopic range of 100 mm, the resonance frequency f (/ min) of the lead wire 10 can be lowered. Dog expression knife β form (form 4)

f = 60 xl / 2 7Γ χ (9 · 8/2 · 0 5) 1/2 = 2 0 · 9 苐 5 The figure shows the length of the wind phase compressed to the minimum, and the length of the straightened steam section is 1 0 0 A schematic diagram of a single crystal of 0 mm at 12 hours. The center of gravity position G of the single crystal 2 is 50 mm below the upper end of the straight portion, and the length of the pendulum L4, that is, the length from the center of the lead wire curling drum 1 to the center of gravity position G is 125 °. The L 2 shown is 100 mm shorter. Therefore, the resonance frequency f (/ min) of the lead wire 10 can be expressed by the following formula: 'f-60 xl / 2 π x (9. 8/1. 25) 1/2 = 26.7 (Eq. 5) In short' From the time when the seed crystals are immersed in the melt to the end of the single crystal incubation

At this time, the frequency f of the seed axis resonance frequency changes between 20.9 and 26.7. Now, an embodiment of a single crystal pulling method using a single crystal pulling device having the above-mentioned resonance frequency number will be described. & Figure 6 shows the single crystal pulling method of the first embodiment, the main purpose of which

Page 9 482832 V. Description of the invention (7) In order to reduce the change of resistivity in the wafer surface. It is indicated by dotted lines. When the bellows is extended, the frequency number shown in the formula 2 types / shaft resonance frequency (/ min) varies between the above formulas. ^ The frequency number a to the formula 3 镫 π in The frequency number c from Equation 4 to the frequency iΗ „shown in Equation 5 varies, that is, between 29.9 and 26.7. Π μ 4 at the limit of the sound frequency between the female frequency number d and the female frequency number d. Shefeng phase 4 is extended to the most fertile! Crystals are immersed in melt 9 and begin to crystallize 12

-Straight from the beginning to the end, the crystal rotation speed S / R ^ T t; P; #; a!: B ^ 30%, msi number a changes to the frequency h & The frequency number is maintained from the frequency interval 'to make the length of the bellows; to :, Γ; ΐ = Λ * enter τ Zhao advises the painter, you switch the resonance frequency of the Japanese-Japanese axis i: number C, to the frequency number The straight line of d. At this time, the moving speed of the gantry 「ν"-(ν ^ Λ '/ U lead wire's curling speed is controlled within 5 minutes) The number of positive resonance frequencies of the species rises from 20.9 to "7". Although S / R is often maintained at 20 rpm, except for the D interval, 镅

The rate is always separated by more than 2 rp m from the resonance frequency of the seed axis. In addition, the cesium # rotation speed C / R is 8 rpm within a curing rate of 50%, and the ratio of ^ and C / R is maintained at more than 2.0 times. The single crystal with a length of 1000mm in the S / R straight part was rear-wheeled at the end of the growth = 13 and raised again with the smart table 14 to extend the bellows 4 to the maximum. Then, the single crystal 12 is accommodated in the drawing chamber 5 and the single crystal 12 is removed from the side portion of the drawing chamber 5 i. VIII. V. Description of the invention (8) ____ Figure 7 shows the comparison of the pulling method according to the first embodiment and: the single crystal obtained by the conventional technology, the resistivity of the two ::,: the position of the two = The single crystal is grown on the top. Since the top frequency is 171 and the seed axis at the bottom is altogether S, the crystal rotation speed S / R becomes 15 rpm. In addition, the number of X 'doors is ~ 90% is the curing rate of the house ρ 〇 mouth' curing rate 0 margin ~ + the shoulder to the end of the day, and the evaluation needle image of the wafer is at a curing rate of 10 In the range of ~ 80%. $ Object Reduction Small in-plane resistivity deviation. Figure 8 shows the single crystal pulling method of the second embodiment to reduce fatigue and noise near the top. The main purpose of the cat 4 is to expose the degree. The seed axis resonance frequency (/ min) and the first ## example, when the bellows is extended, the frequency from the formula 2 family kg * the frequency of the second brother 1 wide frequency b, when the bellows is compressed, the 'j formula 3 The frequency d is shown. In the case of Dan Cheng, the frequency C of the female laborer changed to the formula 5 1 〇, ri. As soon as the sun and the moon were formed, the carbon driver 13 as shown in Fig. 1 was driven, so that the platform would "rise up, For all the bolts, immerse the seed crystals in solution 9 and start the growth of the crystals in the single state. The solidification rate will be 35%. The early two suns will be 12 months old. From the single knot in 23 coffee, then slowly drop to 18re ',' 'm speed S / R is maintained and maintained. Furthermore, under the solid',% = 2 end Duwei interval), when the wind box # 真 caten 4 (brothers up to U 1S interval (S1 The number a changes to the frequency of the number b. The resonance frequency number is reduced from the frequency to the minimum. The seed crystal resonance H interval 'makes the length of the bellows 4 to the straight line of the frequency number d. Here, A adds Switch to the change from the frequency c. 〇 Wood's moving speed Vc = -20〇mm / min 482832 Invention description (9) — '= The curl speed of the crystal pull wire is controlled to Vw within 5 minutes, = (Vw + 2〇 〇_) / min. After the above switching, it becomes the second S section (S2 section), the number of seed axis resonance frequencies. It rises to a straight line that changes from 20 · 9 to 26 · 7. In this embodiment, ,,, Out of T interval The crystal rotation speed g / R is also separated from the resonance frequency by more than 2 rpm. Furthermore, the crucible rotation speed C / R is at the curing rate ^ ⑽, and then 8 rpm. 疋 5 Figure 9 shows a comparison according to the second embodiment. The single point obtained by the drawing method and the single knot mz ,,, etc. obtained according to the conventional technology are set to U =, and the lead wire curling drum 1 corresponding to FIG. Sun, moon and moon, since the top is 17 · 1, the bottom is ## 吐 今 从 from * Riri, the frequency of singular crystal rotation speed s / κΛ%, the frequency of vibration is 19.9 ', so the knot rate is 10 ~ 8n The range of the object is the same as that of the object. The range of the object is limited to the implementation of the single crystal obtained by the solidification and drawing method, and more specifically, the curing rate i ~ 20% nn is more in the presence of a lower oxygen concentration. Near the top, the oxygen concentration is lower than that of a conventional person. [Effect of the invention] As mentioned above, with the present invention, ascending and descending, by this way, the lead wire can be curled into a single crystal when it is required to be eaten ☆ The center of gravity is more "The center of this drum is very easy to grow single crystals. The resonance frequency, because of the resonance frequency Above at least 2 rpm, the second choice is a single crystal with a longer quality than the seed crystal axis. And it is very easy to get the 482832 five-set long shrinkage rate. Fig. 1 is a schematic longitudinal sectional view of a single crystal manufacturing equipment using the single crystal pulling method of the present invention. Fig. 2 shows the length of the pendulum accompanying the progress of the project when the bellows of the single crystal manufacturing apparatus shown in Fig. 1 is extended at the maximum. Fig. 3 shows the change in the length of the pendulum accompanying the progress of the project when the bellows of the single crystal manufacturing apparatus shown in Fig. 1 is at its maximum extension. Fig. 4 shows the change in the length of the pendulum accompanying the progress of the process at the minimum pressure of the bellows of the single crystal manufacturing apparatus shown in Fig. 1. Fig. 5 shows the change in the length of the pendulum accompanying the progress of the process at the minimum pressure of the bellows of the single crystal manufacturing apparatus shown in Fig. 1. FIG. 6 shows changes in the resonance frequency of the seed crystal axis, the rotation speed of the crystal, and the rotation speed of the crucible in the single crystal pulling in the first embodiment. Fig. 7 is a comparison of the in-plane resistivity deviation between the first embodiment and the conventional example. Fig. 8 shows the seed crystal resonance frequency, crystal rotation speed, and pan rotation speed in the single crystal pull of the second embodiment. The change. Fig. 9 is a comparison diagram of the oxygen concentration of single crystals in the second embodiment and the conventional example. Fig. 10 is an explanation of the pendulum movement of the crystal pulling lead and the seed crystal. 3 Vacuum container

Page 13 482832 V. Description of the invention (π) 4 Bellows 5 Pull-out chamber 6 Main chamber 9 Melt 10 Pull-lead 12 13 14 15 Single crystal Bolt Bench Seed crystal < 1

Page 14

Claims (1)

482832 Scope of patent application1. A single crystal pulling method, including the use of the cz method, while changing the seed crystal according to the degree of growth of the single crystal: ,,, and the rate of crystal branches to cross the number of crystal rotations, while growing a single crystal Crystal (丨 2). 9 Resonant cheek 2 · According to the single crystal pulling bow described in item 1 of the scope of the patent application, the single crystal pulling method is to maintain the crystal rotation speed at a high speed on the top of the grown single crystal (1 2), In order to reduce the oxygen concentration, the crystal rotation speed is maintained at a low speed in the vicinity of the near-time portion to prevent the deformation of the second base 12). It is characterized in that in this method, the top of the breeding is ^ attached ^^^^ The seed crystal axis resonance frequency is set to be lower than the crystal rotation speed, and in the vicinity of the female part, the seed crystal axis resonance frequency is set to be higher than the crystal rotation speed. 1 · The single crystal pulling method as described in item 1 or 2 of the scope of the patent application, wherein the single crystal is bred by the S interval and the T interval (丨 2), and the s interval is the resonance of the seed crystal axis The frequency is set to differ from the crystal rotation speed by more than 2 rpm. The T interval is to cross the resonance frequency of the seed crystal axis and the number of crystal rotation speeds within a time that does not hinder the growth of the single crystal (12).