JPS63285428A - Temperature measuring apparatus for semiconductor substrate - Google Patents
Temperature measuring apparatus for semiconductor substrateInfo
- Publication number
- JPS63285428A JPS63285428A JP62122207A JP12220787A JPS63285428A JP S63285428 A JPS63285428 A JP S63285428A JP 62122207 A JP62122207 A JP 62122207A JP 12220787 A JP12220787 A JP 12220787A JP S63285428 A JPS63285428 A JP S63285428A
- Authority
- JP
- Japan
- Prior art keywords
- infrared light
- semiconductor substrate
- temperature
- infrared rays
- wavelength
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Pending
Links
- 239000000758 substrate Substances 0.000 title claims abstract description 77
- 239000004065 semiconductor Substances 0.000 title claims abstract description 48
- 238000005259 measurement Methods 0.000 claims abstract description 35
- 238000004364 calculation method Methods 0.000 claims description 3
- 230000001678 irradiating effect Effects 0.000 claims description 2
- 230000005855 radiation Effects 0.000 abstract description 24
- 238000010438 heat treatment Methods 0.000 description 15
- 230000003287 optical effect Effects 0.000 description 14
- 230000003595 spectral effect Effects 0.000 description 7
- 238000002834 transmittance Methods 0.000 description 7
- 238000009529 body temperature measurement Methods 0.000 description 5
- 238000010586 diagram Methods 0.000 description 5
- 238000000034 method Methods 0.000 description 5
- 238000000137 annealing Methods 0.000 description 3
- 150000002500 ions Chemical class 0.000 description 3
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 230000004913 activation Effects 0.000 description 2
- 230000036760 body temperature Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 230000001419 dependent effect Effects 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000011109 contamination Methods 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- 238000005516 engineering process Methods 0.000 description 1
- 238000005530 etching Methods 0.000 description 1
- 239000012535 impurity Substances 0.000 description 1
- WPYVAWXEWQSOGY-UHFFFAOYSA-N indium antimonide Chemical compound [Sb]#[In] WPYVAWXEWQSOGY-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 239000010453 quartz Substances 0.000 description 1
- VYPSYNLAJGMNEJ-UHFFFAOYSA-N silicon dioxide Inorganic materials O=[Si]=O VYPSYNLAJGMNEJ-UHFFFAOYSA-N 0.000 description 1
- 238000004544 sputter deposition Methods 0.000 description 1
- 230000002123 temporal effect Effects 0.000 description 1
Landscapes
- Radiation Pyrometers (AREA)
Abstract
Description
【発明の詳細な説明】
Ａ、産業上の利用分野
本発明は、シリコン基板のように赤外光を透過
゛する半導体基板の温度を放射温度計を用いて測定する
温度測定方法およびその装置に関する。[Detailed description of the invention] A. Industrial application field
The present invention relates to a temperature measurement method and apparatus for measuring the temperature of a semiconductor substrate using a radiation thermometer.
Ｂ、従来の技術
ＩＣチップのような半導体の製造プロセスにおいては、
半導体基板、例えばシリコン基板にイオンを注入した後
にその基板をアニールする必要がある。近年、不純物拡
散を防止するため、数十秒の加熱時間でアニーリングで
きる光加熱装置が用いられてきたのに伴い、短時間にて
基板の温度を測定し加熱温度を制御することが要求され
ている。B. Conventional technology In the manufacturing process of semiconductors such as IC chips,
After implanting ions into a semiconductor substrate, for example a silicon substrate, it is necessary to anneal the substrate. In recent years, in order to prevent impurity diffusion, optical heating devices that can perform annealing in a few tens of seconds have been used, and as a result, there is a need to measure the temperature of the substrate and control the heating temperature in a short period of time. There is.
そこで従来は、
■ 熱電対を用いて温度を測定したり、あるいは■ 放
射温度計を用いて基板の分光放射輝度を測定し、予め測
定された基板の放射率と測定された分光放射輝度とに基
づいて、周知のＰｌａｎｃｋの式から温度を求めている
。Therefore, conventionally, the temperature was measured using a thermocouple, or the spectral radiance of the board was measured using a radiation thermometer, and the pre-measured emissivity of the board was combined with the measured spectral radiance. Based on this, the temperature is determined from the well-known Planck equation.
しかし、■については、熱電対を基板表面に取付けるこ
とによる汚染や、熱電対と基板表面温度との差が問題と
なっていた。However, regarding (2), there were problems with contamination caused by attaching the thermocouple to the substrate surface and the difference in temperature between the thermocouple and the substrate surface.
また、■については、■の問題点は解決されるもののド
ーピング濃度によって半導体基板ごとに放射率が異なり
、更に基板の温度上昇に伴い放射率が変化し、精度よく
温度測定ができなかった。Regarding (2), although the problem (2) was solved, the emissivity of each semiconductor substrate differed depending on the doping concentration, and the emissivity changed as the temperature of the substrate increased, making it impossible to accurately measure temperature.
ところで、特開昭５９−１０５７７４号公報や特開昭５
３−１２０４８１号公報には、被測温対象物から放射さ
れる赤外光を２波長域に分割して検出し、放射率が未知
である被測温対象物の温度を測定する装置が開示されて
いる。By the way, Japanese Patent Application Laid-open No. 59-105774 and Japanese Patent Application Laid-open No. 5
Publication No. 3-120481 discloses a device that measures the temperature of an object whose emissivity is unknown by dividing and detecting infrared light emitted from the object into two wavelength regions. has been done.
Ｃ０発明が解決しようとする問題点
しかしながら、前者では、２波長域における被測温対象
物の放射率が等しいものと仮定して温度を演算している
ので、各波長域で放射率が大きく変動する条件下では精
度のよい測温が望めない。Problems to be solved by the C0 invention However, in the former method, the temperature is calculated assuming that the emissivity of the object to be measured is equal in the two wavelength ranges, so the emissivity varies greatly in each wavelength range. Under such conditions, accurate temperature measurement cannot be expected.
また、後者では、放射率がほぼ等しくなるほどに近接し
た２波長域を用いているため、両波長域における赤外線
強度がほぼ等しくなってしまい、測温誤差が大きくなっ
てしまう。Furthermore, in the latter case, two wavelength ranges are used so close that the emissivities are almost equal, so the infrared infrared intensities in both wavelength ranges become almost equal, resulting in a large temperature measurement error.
本発明の目的は、種々の放射率やドーピング濃度をもつ
各種の半導体基板の温度を精度よく測定できる半導体基
板の温度測定装置を提供することにある。An object of the present invention is to provide a semiconductor substrate temperature measuring device that can accurately measure the temperature of various semiconductor substrates having various emissivities and doping concentrations.
Ｄ０問題点を解決するための手段
放射温度計による半導体基板の測定原理について説明す
る。Means for Solving the D0 Problem The principle of measuring a semiconductor substrate using a radiation thermometer will be explained.
放射温度計で測定される基板の分光放射輝度Ｎ（λ、Ｔ
）は、一般的に、
Ｎ（λ、Ｔ）＝ε（λ、 Ｔ）・Ｗ（λ、 Ｔ）
・・・（１）ただし、ε（λ、Ｔ）二基板の放射率
Ｗ（λ、Ｔ）：黒体の分光放射輝度
と表せる。また、黒体の分光放射輝度Ｗ（λ、Ｔ）は。The spectral radiance N(λ, T
) is generally expressed as N(λ, T)=ε(λ, T)・W(λ, T)
... (1) However, emissivity W (λ, T) of the two substrates ε (λ, T) can be expressed as the spectral radiance of a black body. Also, the spectral radiance W(λ, T) of a black body is.
ただし、Ｃ□、Ｃｔ：定数
λ：放射光波長
Ｔ：黒体温度
と表せる。したがって、基板の放射率Ｅ（λ、Ｔ）を与
えれば、放射温度計の測定値から求まるＮ（λ、Ｔ）に
基づき（１）式から黒体の分光放射輝度Ｗ（λ、Ｔ）が
求まり、更に（２）式から黒体温度Ｔを求めれば、この
値が基板の温度を示す。However, C□, Ct: constant λ: radiation wavelength T: black body temperature. Therefore, if the emissivity E(λ, T) of the substrate is given, the spectral radiance W(λ, T) of the black body can be calculated from equation (1) based on N(λ, T) determined from the measured value of the radiation thermometer. If the black body temperature T is determined from equation (2), this value indicates the temperature of the substrate.
一方、基板の放射率Ｅ（λ、Ｔ）は、
ε（λ、Ｔ）＝１−（τ（λ、 Ｔ）＋ρ（λ、Ｔ））
・・・（３）、 ただし、ε（λ、Ｔ）：基板の放射
率ρ（λ、Ｔ）二基板の多重反射を含めた反射率で（λ
、Ｔ）二基板の多重反射を含めた透過率と表せる。ρ（
λ、Ｔ）は基板の屈折率ｎに関係する値であるから、
ρ＝ρ （ｎ） ・・・（４）と表
わすことができ、屈折率ｎは、
ｎ＝ｎ （λ、Ｔ、Ｄ） ・・・（５）ただし
、Ｄはドーピング濃度
と表わすことができる。第６図は、Ｔ＝常温。On the other hand, the emissivity E(λ, T) of the substrate is ε(λ, T)=1−(τ(λ, T)+ρ(λ, T))
...(3), where ε(λ, T): emissivity of the substrate ρ(λ, T) is the reflectance including multiple reflections of the two substrates (λ
, T) can be expressed as the transmittance including multiple reflections of the two substrates. ρ(
Since λ, T) are values related to the refractive index n of the substrate, they can be expressed as ρ=ρ (n) ...(4), and the refractive index n is n=n (λ, T, D )...(5) However, D can be expressed as doping concentration. In Figure 6, T = room temperature.
Ｄ＝Ｏにおけるシリコンの波長−屈折率特性のグラフで
あり、波長１μｍ以上の領域で屈折率ｎが波長に依存し
ないことを示している。このことから、本明細書におい
ては、ある温度とあるドーピング濃度に対しては屈折率
ｎが波長に依存せず一定であると仮定する。したがって
、（５）式は。It is a graph of the wavelength-refractive index characteristic of silicon at D=O, and shows that the refractive index n does not depend on wavelength in a wavelength region of 1 μm or more. Therefore, in this specification, it is assumed that the refractive index n is constant regardless of the wavelength for a certain temperature and a certain doping concentration. Therefore, equation (5) is.
ｎ＝ｎ （Ｔ、Ｄ） ・・・（６）となり
、この（６）式から、（４）式は、ρ＝ρ （Ｔ、Ｄ）
・・・（７）と表わすことができる。n=n (T, D) ...(6), and from this equation (6), equation (4) becomes ρ=ρ (T, D)
...(7) can be expressed.
そこで、ドーピング濃度を考慮しく７）式を用いて（３
）式を書き直すと、Ｅ（λ、 Ｔ、 Ｄ）＝１−τ（λ
、 Ｔ、 Ｄ）−ρ（Ｔ、 Ｄ）・・・（８）となるか
ら、（１）式は、一般式として、Ｎ （λｐＴ、Ｄ）
＝ （１−ｔ （λ、Ｔ 、Ｄ） ｐ （Ｔ −Ｄ）
） Ｗ（λ、Ｔ）・・・（９）
と表わされる。Therefore, considering the doping concentration, using equation 7), (3
) rewriting the equation, E(λ, T, D)=1−τ(λ
, T, D) - ρ(T, D)...(8), so equation (1) can be expressed as a general equation by N (λpT, D)
= (1-t (λ, T, D) p (T-D)
) W(λ, T)...(9)
ここで、所定のドーピング濃度の基板についてＮ（λ、
Ｔ、Ｄ）と、τ（λ、Ｔ、Ｄ）とを測定して既知の値と
し、ρ（Ｔ、Ｄ）とＷ（λ、Ｔ）を未知数とする。２つ
の波長λＡ、λＢについてそれぞれ、
Ｎ＾＝（１−τＡ−ρ（Ｔ） ） Ｗ（λＡｐＴ）
・・・（１０）ＮＢ＝（１−τＢ−ρ（Ｔ） ） Ｗ
（λａ＊Ｔ） ・・・（１１）ただし、Ｎ＾＝Ｎ（
λＡｓ Ｔ）ｒ Ｎａ＝Ｎ（λａ＊Ｔ）τ＾＝τ（λＡ
？ Ｔ） ｖ ｆＢ冨τ（λｎｐＴ）の２式を考えれば
、ρ（Ｔ）、Ｔが求まる。ここで、Ｎ（λＡｔ ’ｒ）
Ｐ Ｎ（λｇｐＴ）は後述する第１及び第２の赤外光
量測定手段１０３，１０４の出力である。また、τＡ、
τＢは、半導体基板に測定用赤外光を照射してその透過
光を含む半導体基板からの第１状態、の赤外光量を測定
するとともに、測定用赤外光を含まない半導体基板から
の第２状態の赤外光量を測定し、これら第１状態および
第２状態の赤外光量の差に基づき容易に算出される。Here, for a substrate with a predetermined doping concentration, N(λ,
T, D) and τ(λ, T, D) are measured to be known values, and ρ(T, D) and W(λ, T) are unknown values. For the two wavelengths λA and λB, respectively, N^=(1-τA-ρ(T)) W(λApT)
...(10)NB=(1-τB-ρ(T)) W
(λa*T) ... (11) However, N^=N(
λAs T)r Na=N(λa*T)τ^=τ(λA
? If we consider the two equations of T) v fB-density τ(λnpT), ρ(T) and T can be found. Here, N(λAt 'r)
P N (λgpT) is the output of first and second infrared light amount measuring means 103 and 104, which will be described later. Also, τA,
τB is determined by irradiating the semiconductor substrate with infrared light for measurement and measuring the amount of infrared light from the semiconductor substrate in the first state that includes the transmitted light, and in the first state from the semiconductor substrate that does not include the infrared light for measurement. The amount of infrared light in two states is measured, and it is easily calculated based on the difference between the amounts of infrared light in the first state and the second state.
そこで本発明装置は、第１図のクレーム対応図に示すと
おり、半導体基板１０１に測定用の互いに異なる第１及
び第２の波長を含む赤外光を照射する照射手段１０２と
、半導体基板１０１に関して照射手段１０２と反対側に
配置された、半導体基板１０１からの第１の波長の赤外
光量を測定するための第１の赤外光量測定手段１０３．
および半導体基板１０１からの第２の波長の基外光量を
測定するための第２の赤外光量測定手段１０４と、測定
用赤外光を含む半導体基板１０１からの第１赤外光量を
測定する第１状態と、測定用赤外光の光量を含まない半
導体基板１０１からの第２赤外光量を測定する第２状態
とを切り換える切換手段１０５と、第１および第２の赤
外光量測定手段１０３．１０４でそれぞれ測定される第
１状態及び第２状態の赤外光量のそれぞれの差と、各第
２状態の赤外光量とに基づいて半導体基板１０１の温度
を算出する演算手段１０６とを具備する。Therefore, as shown in the claim-corresponding diagram of FIG. A first infrared light amount measuring means 103 for measuring the amount of infrared light of the first wavelength from the semiconductor substrate 101, which is disposed on the opposite side of the irradiation means 102.
and a second infrared light amount measuring means 104 for measuring the amount of extra-base light of the second wavelength from the semiconductor substrate 101, and a second infrared light amount measuring means 104 for measuring the amount of the first infrared light from the semiconductor substrate 101 including measurement infrared light. A switching means 105 that switches between a first state and a second state that measures a second amount of infrared light from the semiconductor substrate 101 that does not include the amount of infrared light for measurement, and first and second infrared light amount measuring means. 103. Calculating means 106 calculates the temperature of the semiconductor substrate 101 based on the difference between the amounts of infrared light in the first state and the second state measured at 104, and the amount of infrared light in each second state. Be equipped.
８０作用
照射手段１０２は測温用の互いに異なる第１及び第２の
波長を含む赤外光を照射する。切換手段１０５により第
１の状態を得、半導体基板１０１を透過する測定用赤外
光による寄与分と半導体基板自身の温度による放射赤外
光による寄与分とを重ね合わせた第１状態の赤外光量を
第１および第２の赤外光量測定手段１０３，１０４で測
定する。The 80 action irradiation means 102 irradiates infrared light including first and second wavelengths different from each other for temperature measurement. A first state is obtained by the switching means 105, and the first state of infrared light is obtained by superimposing the contribution of the measurement infrared light transmitted through the semiconductor substrate 101 and the contribution of the emitted infrared light due to the temperature of the semiconductor substrate itself. The amount of light is measured by first and second infrared light amount measuring means 103 and 104.
また切換手段１０５により第２の状態を得、半導体基板
自身の温度による第２状態の赤外光量を各測定手段１０
３，１０４で測定する。そして、演算手段１０６におい
て、各波長域における第１状態および第２状態の赤外光
量の差と、各波長域における第２状態の赤外光量とに基
づいて半導体基板１０１の温度を算出する。Further, a second state is obtained by the switching means 105, and each measuring means 10 measures the amount of infrared light in the second state depending on the temperature of the semiconductor substrate itself.
Measured at 3,104. Then, the calculation means 106 calculates the temperature of the semiconductor substrate 101 based on the difference in the amount of infrared light between the first state and the second state in each wavelength range and the amount of infrared light in the second state in each wavelength range.
Ｆ、実施例
第２図〜第５図に基づいて、半導体基板をアニーリング
する光加熱装置に本発明を適用した場合について説明す
る。F. Embodiment A case in which the present invention is applied to an optical heating device for annealing a semiconductor substrate will be described based on FIGS. 2 to 5.
第２図（ａ）において、チャンバ１内の基台２上に半導
体基板３が載置される。チャンバ１の上壁１ａ、下ｕｌ
ｂには、第２図（ｂ）に示すように、半径が異なりそれ
ぞれ同心円状に配置された６本の加熱用赤外ランプ４ａ
、４ｂ、４ｃ、５ａ。In FIG. 2(a), a semiconductor substrate 3 is placed on a base 2 in a chamber 1. As shown in FIG. Upper wall 1a of chamber 1, lower ul
As shown in FIG. 2(b), there are six heating infrared lamps 4a arranged concentrically with different radii.
, 4b, 4c, 5a.
５ｂ、５ｃが設置され、半導体基＠３を加熱する。5b and 5c are installed to heat the semiconductor substrate @3.
上壁１ａ、下壁１ｂの中心にはそれぞれ対向する貫通孔
１ｃ、ｌｄがあけられ、それら孔の上方には１例えば３
〜５μｍの波長帯の赤外線を出射する測定用赤外ランプ
６が設けられ、その出射光がレンズ７で平行光とされる
。その平行光の光路を開閉するチョッパ８が軸９の回り
に回動可能に軸支され、図示しない駆動装置によって光
路が開閉される。また、半導体基板３を挟んで測定用赤
外ランプ６とは反対側にビームスプリッタ１ｏが設けら
れて測定用赤外光は２つの光路に分岐される。一方の光
路には波長λＡの赤外光のみを透過するフィルタｌｌａ
が、他方の光路には波長λＢ（≠λＡ）の赤外光のみを
透過するフィルタ１１ｂが設けられる。各フィルタｌｌ
ａ、ｌｌｂを通過した赤外光は集光レンズ１２ａ、１２
ｂを介して波長λ入用の放射温度計１３ａと波長λＢ用
の放射温度計１３ｂとに入射される。Opposing through holes 1c and ld are formed in the centers of the upper wall 1a and the lower wall 1b, respectively.
A measurement infrared lamp 6 that emits infrared light in a wavelength band of ~5 μm is provided, and the emitted light is converted into parallel light by a lens 7. A chopper 8 that opens and closes the optical path of the parallel light is rotatably supported around a shaft 9, and the optical path is opened and closed by a drive device (not shown). Further, a beam splitter 1o is provided on the opposite side of the measurement infrared lamp 6 across the semiconductor substrate 3, so that the measurement infrared light is split into two optical paths. On one optical path, there is a filter lla that transmits only infrared light of wavelength λA.
However, the other optical path is provided with a filter 11b that transmits only infrared light of wavelength λB (≠λA). Each filter
The infrared light that has passed through a and llb is collected by condenser lenses 12a and 12.
The radiation enters the radiation thermometer 13a for the wavelength λ and the radiation thermometer 13b for the wavelength λB through the wavelength λB.
第３図にこの装置の制御部を示す。放射温度計１３ａ、
１３ｂがマイクロコンピュータ２２と接続され測定され
た各波長域λ＾、λＢの赤外光量Ｎ Ａｒ Ｎ Ｂが入
力される。マイクロコンピュータ２２には、チョッパ８
の駆動回路２３と、測定用赤外ランプ６の駆動制御回路
２４と、加熱用赤外ランプ４ａ〜４ｃ、５ａ〜５Ｃの駆
動制御回路２５と、温度表示計２６とが接続している。FIG. 3 shows the control section of this device. radiation thermometer 13a,
13b is connected to the microcomputer 22, and the measured amounts of infrared light N Ar N B in each wavelength range λ^ and λB are input. The microcomputer 22 has a chopper 8.
A drive control circuit 24 for the measurement infrared lamp 6, a drive control circuit 25 for the heating infrared lamps 4a to 4c and 5a to 5C, and a temperature indicator 26 are connected.
以上の構成において、測定用赤外ランプ６が照射手段１
０２を１、放射温度計１３ａ、１３ｂが第１及び第２の
赤外光量測定手段１．０３，１０４を、チョッパ８．そ
の駆動回路２３が切換手段１０５を、マイクロコンピュ
ータ２２が演算手段１０６をそれぞれ構成している。In the above configuration, the measurement infrared lamp 6 is used as the irradiation means 1.
02 as 1, the radiation thermometers 13a and 13b as the first and second infrared light amount measuring means 1.03, 104, and the chopper 8. The drive circuit 23 constitutes the switching means 105, and the microcomputer 22 constitutes the calculation means 106.
次に第４図の処理手順と第５図のグラフにしたカモって
この温度測定装置の動作を説明する。Next, the operation of the temperature measuring device shown in the processing procedure shown in FIG. 4 and the graph shown in FIG. 5 will be explained.
まず、ランプ６から出射される赤外光はビームスプリッ
タ１０．各波長フィルタｌｌａ、ｌｌｂ。First, the infrared light emitted from the lamp 6 is transmitted to the beam splitter 10. Each wavelength filter lla, llb.
集光レンズ１２ａ、１２ｂを介して放射温度計１３ａ、
１３ｂに入射される。まず、基板３を基台２上に載置し
ない状態で、測定用赤外ランプ６を点灯する。放射温度
計１３ａ、１３ｂは、各波長域λＡ、λＢごとに赤外ラ
ンプ６の出射赤外光量を測定して光量出力データＮＡＯ
，ＮＢＱを出力し。A radiation thermometer 13a through condensing lenses 12a and 12b,
13b. First, the measurement infrared lamp 6 is turned on without the substrate 3 being placed on the base 2. The radiation thermometers 13a and 13b measure the amount of infrared light emitted from the infrared lamp 6 in each wavelength range λA and λB, and obtain light amount output data NAO.
, NBQ is output.
そのデータＮＡＯ，ＮＢＯをマイクロコンピュータ２２
に記憶する。尚、測定用赤外ランプ６から供給される光
量は制御回路２４により少なくとも測定中は一定と成る
ように制御されている。The data NAO and NBO are sent to the microcomputer 22.
to be memorized. Note that the amount of light supplied from the measurement infrared lamp 6 is controlled by the control circuit 24 so that it remains constant at least during measurement.
そして、載置台２に半導体基板３を載置した後にマイク
ロコンピュータ２２によって第４図のプログラムがスタ
ートする。ステップＳ１でチョッパ駆動回路２３を駆動
してチョッパ８により測定用赤外光の光路を閉じる。赤
外ランプ６からの出射光はレンズ７で平行光とされるが
チョッパ８で遮られ基板３上には達しない。このとき加
熱用赤外ランプ４ａ〜４ｃ、５ａ〜５ｃにより基板３が
加熱されており、基板３の表面温度に依存する赤外光が
放射される。その放射赤外光のうち波長λＡの光線は放
射温度計１３ａに、波長λＢの光線は放射温度計１３ｂ
に入射される。例えば第５図の時点ｔ工。では基板３の
分光放射輝度に対応した各放射温度計１３ａ、１３ｂの
出力データＮＡＩ。After the semiconductor substrate 3 is placed on the mounting table 2, the program shown in FIG. 4 is started by the microcomputer 22. In step S1, the chopper drive circuit 23 is driven to close the optical path of the measuring infrared light by the chopper 8. The light emitted from the infrared lamp 6 is converted into parallel light by a lens 7, but is blocked by a chopper 8 and does not reach the substrate 3. At this time, the substrate 3 is heated by the heating infrared lamps 4a to 4c and 5a to 5c, and infrared light depending on the surface temperature of the substrate 3 is emitted. Among the radiated infrared light, a ray of wavelength λA is sent to a radiation thermometer 13a, and a ray of wavelength λB is sent to a radiation thermometer 13b.
is incident on the For example, at time t in Figure 5. Now, output data NAI of each radiation thermometer 13a, 13b corresponding to the spectral radiance of the substrate 3.
ＮＢＩを記憶する（ステップＳ２）。The NBI is stored (step S2).
次いでチョッパ駆動回路２３を駆動してチョッパ８によ
り測定用赤外光の光路を開く（人テップＳ３）、これに
より、測定用赤外ランプ６からの赤外光が基板３上に照
射される。この赤外光は基板３のドーピング濃度や注入
したイオンの活性化状態、あるいは温度に依存した割り
合いで基板３を透過する。したがって、その透過光と温
度に依存する基板３からの放射光とが、放射温度計１３
ａ、１３ｂに入射され、両者の合成出力データＮＡｌ’
ＮＢ１’ が出力される。マイクロコンピュータ２２は
これらのデータＮＡＩ’ ＮＢＩ’ を記憶する（ステ
ップＳ４）。Next, the chopper drive circuit 23 is driven to open the optical path of the measuring infrared light by the chopper 8 (step S3), whereby the substrate 3 is irradiated with the infrared light from the measuring infrared lamp 6. This infrared light is transmitted through the substrate 3 at a rate that depends on the doping concentration of the substrate 3, the activation state of the implanted ions, or the temperature. Therefore, the transmitted light and the temperature-dependent emitted light from the substrate 3 are transmitted to the radiation thermometer 13.
a, 13b, and the combined output data NAl' of both
NB1' is output. The microcomputer 22 stores these data NAI'NBI' (step S4).
次いでステップＳ５において、予め測定された測定用赤
外ランプ６からの赤外光が基板３を介さずに直接入射し
たときの放射温度計１３ａ。Next, in step S5, the radiation thermometer 13a receives the infrared light from the measuring infrared lamp 6 which has been measured in advance and directly enters the radiation thermometer 13a without passing through the substrate 3.
１３ｂの出力データＮＡＯ，ＮＢＯと、上述したデータ
ＮＡＩ、ＮＢＩ、ＮＡＩ’ ＮＢＩ’ とにより。13b's output data NAO, NBO and the above-mentioned data NAI, NBI, NAI'NBI'.
（ＮＡ’ｌ’−ＮＡＩ）／ＮＡＯ＝τＡ１ ・・・（１
４）（Ｎａｌ″−Ｎｓｌ）／Ｎａ０＝τＢ１ ・・・（
１５）を計算し、測定時点し□。の・透過率τＡｌｙ
τＢ１を求める。但し、基板内に設けられたパターンに
よる回折等の原因で基板を透過した測定用赤外光の一部
が放射温度計１３ａ、１３ｂからはずれた場合には、’
ＮＡＩ’ ＮＢＩ’に補正が必要となる６次に、これら
透過率でＡｌｅ τＢ１とＮＡＩ。(NA'l'-NAI)/NAO=τA1...(1
4) (Nal″-Nsl)/Na0=τB1...(
15) Calculate and measure □. Transmittance τAly
Find τB1. However, if a portion of the measurement infrared light that has passed through the substrate deviates from the radiation thermometers 13a and 13b due to reasons such as diffraction due to a pattern provided within the substrate,
NAI'NBI' needs to be corrected 6th order Ale τB1 and NAI with these transmittances.
ＮＢＩ とから、ＸテップＳ６におイテ、（１０）。From NBI, go to Xtep S6 (10).
（１１）式に基づいて反射率ρ（Ｔ１）と温度Ｔ１とを
求める。そしてステップＳ７において、温度Ｔ１を温度
表示計２６に出力する。また２図示はしていないが、予
め基板加熱設定温度Ｔｓをマイクロコンピュータ２２に
入力し、測定された温度Ｔ１と比較して設定温度Ｔｓに
なるまでランプ駆動制御回路２５に制御信号を供給して
加熱用赤外ランプ４ａ〜４ｃ、５ａ〜５ｃを駆動する。Reflectance ρ(T1) and temperature T1 are determined based on equation (11). Then, in step S7, the temperature T1 is output to the temperature display meter 26. 2.Although not shown, the substrate heating set temperature Ts is input into the microcomputer 22 in advance, and the control signal is supplied to the lamp drive control circuit 25 until the set temperature Ts is reached by comparing it with the measured temperature T1. The heating infrared lamps 4a to 4c and 5a to 5c are driven.
以上の手順（ステップ８１〜Ｓ７）を、第５図の時点ｔ
２゜？ １．。・・・と順次に所定時間間隔で繰り返し
て行なうことにより、放射率やドーピング濃度が未知で
ある基板のアニーリング温度を実時間で精度よく測定で
きる。したがって、この結果に基づき加熱用赤外ランプ
４ａ〜４ｃ、５ａ〜５ｃを制御すれば温度制御の精度も
向上する。The above procedure (steps 81 to S7) is performed at time t in FIG.
2°? 1. . By sequentially repeating the steps . . . at predetermined time intervals, it is possible to accurately measure the annealing temperature of a substrate whose emissivity and doping concentration are unknown in real time. Therefore, if the heating infrared lamps 4a to 4c and 5a to 5c are controlled based on this result, the accuracy of temperature control will also be improved.
なお、第５図中、ΔＮＡＩ〜ΔＮＡ３ｔΔＮａｌ〜ΔＮ
Ｂ３が測定用赤外光による寄与分であり。In addition, in FIG. 5, ΔNAI~ΔNA3tΔNal~ΔN
B3 is the contribution from the infrared light for measurement.
測定用赤外ランプ６の光量が一定であるのにかかわらず
高温になるほど減少している。これは、基板３の赤外透
過率τが注入したイオンの活性化状態や温度に依存して
いることを示しているが、本発明の如く、測定時点毎に
この透過率τを求めつつ温度測定を行なうことにより測
定精度が向上する。Although the light intensity of the measurement infrared lamp 6 is constant, it decreases as the temperature increases. This indicates that the infrared transmittance τ of the substrate 3 depends on the activation state of the implanted ions and the temperature. However, as in the present invention, this transmittance τ is determined at each measurement point and the temperature Measurement accuracy improves by performing measurements.
なお、チョッパ８で測定用赤外光の光路を開閉する代り
に、光変調器や偏光素子等をその光路中に設け、半導体
基板３上に照射される測定用赤外光の光量を制御するよ
うにしてもよい。この場合。Note that instead of opening and closing the optical path of the measurement infrared light using the chopper 8, an optical modulator, a polarizing element, etc. is provided in the optical path to control the amount of measurement infrared light irradiated onto the semiconductor substrate 3. You can do it like this. in this case.
半導体基板３を透過した測定用赤外光が放射温度計の出
力にあまり影響を与えない程度の光量であれば、完全に
零にしなくてもよい、また、チョッパ８を省略して、半
導体基板３の所定の領域（例えば中央部）に常時測定用
赤外光を測射し、測定用赤外光が照射されている半導体
基板３の領域と測定用赤外光が照射されていない半導体
基板３の領域とを所定時間ごとに走査することにより、
上述のΔＮＡｉ、ΔＮＢｉを求めてもよい。As long as the amount of infrared light for measurement transmitted through the semiconductor substrate 3 does not significantly affect the output of the radiation thermometer, it is not necessary to completely reduce the amount of infrared light to zero. Infrared light for measurement is constantly measured on a predetermined area (for example, the center part) of the semiconductor substrate 3, and the area of the semiconductor substrate 3 that is irradiated with the infrared light for measurement and the semiconductor substrate that is not irradiated with the infrared light for measurement are measured. By scanning the area 3 at predetermined intervals,
The above-mentioned ΔNAi and ΔNBi may also be determined.
更にまた、ρ（λ、Ｔ）の波長依存性が問題のない波長
帯を用いるときには、放射温度計１３ａ、１３ｂとして
ＩｎＳｂおよびＨｇ Ｃｄ Ｔ ｅによる一体型２色赤
外検知器が使用可能である。Furthermore, when using a wavelength band in which the wavelength dependence of ρ (λ, T) is not problematic, an integrated two-color infrared detector using InSb and Hg Cd Te can be used as the radiation thermometers 13a and 13b. .
この場合、フィルタｌｌａ、１．１ｂが不要となるのに
加えて集光レンズ１２ａ、１２ｂが共通化され温度変動
に対する安定性が増す。In this case, the filters 11a and 1.1b are not necessary, and the condensing lenses 12a and 12b are shared, increasing stability against temperature fluctuations.
なお、反射率ρ（λ、Ｔ）はドーピング濃度にあまり依
存しない値ではあるが、長波長になる程依存性が高くな
る傾向にあるため、測定用赤外光をあまり長い波長とす
ると測定精度が低下する。他方、測定精度の向上のため
には、測定用赤外光と加熱用赤外光とで波長域を分離す
ることが必要であり、このため測定用赤外光の波長をあ
まり短くすることができない６よって、実用上は測定用
赤外光の波長は４〜６μｍ程度が好ましく、加熱用赤外
光としては、石英チャンバを透過し得る４μ以下の波長
を用いることが望ましい。Note that although the reflectance ρ (λ, T) is a value that does not depend much on the doping concentration, it tends to become more dependent on the longer the wavelength. Therefore, if the wavelength of the infrared light for measurement is too long, the measurement accuracy may be affected. decreases. On the other hand, in order to improve measurement accuracy, it is necessary to separate the wavelength ranges of infrared light for measurement and infrared light for heating, and for this reason, it is not possible to make the wavelength of infrared light for measurement too short. Therefore, in practice, the wavelength of the infrared light for measurement is preferably about 4 to 6 μm, and it is desirable to use the infrared light for heating at a wavelength of 4 μm or less that can be transmitted through the quartz chamber.
また本発明は光加熱装置に限らず、光を用いて基板を補
助加熱するスパッタリング装置、エピタキシャル装置、
エツチング装置や、光ＣＶＤ装置あるいは光ドーピング
装置など種々のその温度測定に供することができる。Furthermore, the present invention is not limited to optical heating devices, but also includes sputtering devices, epitaxial devices, and epitaxial devices that use light to supplementally heat a substrate.
It can be used to measure the temperature of various devices such as etching equipment, photo-CVD equipment, and optical doping equipment.
Ｇ０発明の効果
本発明によれば、２波長域の赤外光を用いて各波長ごと
に半導体基板の透過率を求め、これらの透過率と各波長
ごとに検出される測定用赤外光を含まない赤外光光量と
に基づいて半導体基板の温度を測定するようにしたので
、放射率の温度依存性及びドーピング濃度依存性が加熱
時に不明な半導体基板の温度をリアルタイムに測定する
ことができる。G0 Effect of the invention According to the invention, the transmittance of the semiconductor substrate is determined for each wavelength using infrared light in two wavelength ranges, and these transmittances and the measurement infrared light detected for each wavelength are combined. Since the temperature of the semiconductor substrate is measured based on the amount of infrared light not included, it is possible to measure in real time the temperature of a semiconductor substrate whose temperature dependence of emissivity and doping concentration dependence are unknown during heating. .
第１図はクレーム対応図、第２図〜第５図は本発明を光
加熱装置に適用した場合の実施例を説明する図であり、
第２図（ａ）は全体構成図、第２図（ｂ）は加熱ランプ
の平面図、第３図は制御部を示すブロック図、第４図は
処理手順例を示すフローチャート、第５図は放射温度計
の出力の時間変化を示すグラフ、第６図は、常温でドー
ピング濃度が零の場合における波長−屈折率の関係を示
すグラフである。
１：チャンバ ３：半導体基板４ａ〜４．ｃ
、５ａ〜５Ｃ：加熱用赤外ランプ６：測定用赤外ランプ
８：チョッパ１３ａ、１３ｂ：放射温度計
１１：波長フィルタ
１０１：半導体基板 １０２：照射手段１０３．１
０４：第１及び第２の赤外光量測定手段１０５：切換手
段 １０６：演算手段特許出願人 日本光学工
業株式会社
代理人弁理士 永 井 冬 紀
第８図
巳 へ
壇
ｔｆＯｉｆｆ １２０ ｔ２ｆ ｔ、５０ｔ５ｆ＃膚
ｔ −
第５図FIG. 1 is a diagram corresponding to claims, and FIGS. 2 to 5 are diagrams illustrating embodiments in which the present invention is applied to a light heating device.
Fig. 2(a) is an overall configuration diagram, Fig. 2(b) is a plan view of the heat lamp, Fig. 3 is a block diagram showing the control section, Fig. 4 is a flowchart showing an example of the processing procedure, and Fig. 5 is a FIG. 6, a graph showing the temporal change in the output of the radiation thermometer, is a graph showing the relationship between wavelength and refractive index when the doping concentration is zero at room temperature. 1: Chamber 3: Semiconductor substrates 4a to 4. c.
, 5a to 5C: Infrared lamp for heating 6: Infrared lamp for measurement 8: Chopper 13a, 13b: Radiation thermometer 11: Wavelength filter 101: Semiconductor substrate 102: Irradiation means 103.1
04: First and second infrared light amount measuring means 105: Switching means 106: Calculating means Patent applicant Nippon Kogaku Kogyo Co., Ltd. Representative patent attorney Fuyu Nagai Skin t - Figure 5
Claims (1)
波長を含む赤外光を照射する照射手段と、 前記半導体基板に関して前記照射手段と反対側に配置さ
れた、前記半導体基板からの前記第１の波長の赤外光量
を測定するための第１の赤外光量測定手段、および前記
半導体基板からの前記第２の波長の赤外光量を測定する
ための第２の赤外光量測定手段と、 前記測定用赤外光を含む前記半導体基板からの第１赤外
光量を測定する第１状態と、前記測定用赤外光の光量を
含まない前記半導体基板からの第２赤外光量を測定する
第２状態とを切り換える切換手段と、 前記第１および第２の赤外光量測定手段でそれぞれ測定
される第１状態及び第２状態の赤外光量のそれぞれの差
と、各第２状態の赤外光量とに基づいて前記半導体基板
の温度を算出する演算手段と、を具備することを特徴と
する半導体基板の温度測定装置。[Claims] An apparatus for measuring the temperature of a heated semiconductor substrate, comprising: irradiation means for irradiating the semiconductor substrate with infrared light including first and second wavelengths different from each other for measurement; and the semiconductor substrate. a first infrared light amount measuring means for measuring the amount of infrared light of the first wavelength from the semiconductor substrate, which is disposed on the opposite side of the irradiation means; a second infrared light amount measuring means for measuring an amount of infrared light of a wavelength; a first state for measuring a first amount of infrared light from the semiconductor substrate including the measuring infrared light; a switching means for switching between a second state in which a second amount of infrared light from the semiconductor substrate that does not include the amount of external light is measured; and a first state measured by the first and second infrared light amount measuring means, respectively. and calculation means for calculating the temperature of the semiconductor substrate based on the difference in the amount of infrared light in the second state and the amount of infrared light in each second state. measuring device.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122207A JPS63285428A (en) | 1987-05-18 | 1987-05-18 | Temperature measuring apparatus for semiconductor substrate |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP62122207A JPS63285428A (en) | 1987-05-18 | 1987-05-18 | Temperature measuring apparatus for semiconductor substrate |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| JPS63285428A true JPS63285428A (en) | 1988-11-22 |
Family
ID=14830201
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP62122207A Pending JPS63285428A (en) | 1987-05-18 | 1987-05-18 | Temperature measuring apparatus for semiconductor substrate |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS63285428A (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0396247A (en) * | 1989-08-29 | 1991-04-22 | American Teleph & Telegr Co <Att> | Method of manufacturing semiconductor element including light interference temperature measuring method |
| KR20150107090A (en) * | 2014-03-13 | 2015-09-23 | 에이피시스템 주식회사 | Apparatus and method for measuring substrate temperature |
| US10190915B2 (en) | 2002-06-24 | 2019-01-29 | Mattson Technology, Inc. | System and process for calibrating pyrometers in thermal processing chambers |
-
1987
- 1987-05-18 JP JP62122207A patent/JPS63285428A/en active Pending
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH0396247A (en) * | 1989-08-29 | 1991-04-22 | American Teleph & Telegr Co <Att> | Method of manufacturing semiconductor element including light interference temperature measuring method |
| US10190915B2 (en) | 2002-06-24 | 2019-01-29 | Mattson Technology, Inc. | System and process for calibrating pyrometers in thermal processing chambers |
| KR20150107090A (en) * | 2014-03-13 | 2015-09-23 | 에이피시스템 주식회사 | Apparatus and method for measuring substrate temperature |
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