JPH01308080A - Semiconductor nonvolatile memory - Google Patents

Semiconductor nonvolatile memory

Info

Publication number
JPH01308080A
JPH01308080A JP13970988A JP13970988A JPH01308080A JP H01308080 A JPH01308080 A JP H01308080A JP 13970988 A JP13970988 A JP 13970988A JP 13970988 A JP13970988 A JP 13970988A JP H01308080 A JPH01308080 A JP H01308080A
Authority
JP
Japan
Prior art keywords
film
region
tunnel
gate electrode
oxide film
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
Application number
JP13970988A
Other languages
Japanese (ja)
Inventor
Yoshikazu Kojima
芳和 小島
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Seiko Instruments Inc
Original Assignee
Seiko Instruments Inc
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Application filed by Seiko Instruments Inc filed Critical Seiko Instruments Inc
Priority to JP13970988A priority Critical patent/JPH01308080A/en
Publication of JPH01308080A publication Critical patent/JPH01308080A/en
Pending legal-status Critical Current

Links

Abstract

PURPOSE:To provide a strength against a high electric field stress and to prevent an accidental damage due to rewriting by employing a so-called silicon oxynitride film in which silicon nitride film formed by a CVD method is thermally oxidized as a tunnel insulating film. CONSTITUTION:An oxide film 4 is formed on a whole substrate 1, and a region to become a tunnel region is then opened to the substrate 1 by etching the film 4 by a photolithographic step. Then, a CVD silicon nitride film 15 having 100Angstrom or less is formed on a whole surface. Thereafter, the film 15 is thermally oxidized at 900 deg.C or more, and a floating gate electrode 7 made of a thin polycrystalline silicon film is formed thereon. Subsequently, the electrode 7 is oxidized at 1000 deg.C or more to form a control gate oxide film 8, a control gate electrode 9 is formed thereon, and with the electrode 7 as a mask a source region 2 and a drain region 3 are doped to complete a memory.

Description

【発明の詳細な説明】 〔産業上の利用分野〕 この発明は、ICカードなどの記(1川デバイスとして
用いられている半導体不揮発性メモリに関する。
DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to a semiconductor nonvolatile memory used as a device such as an IC card.

〔発明の概要〕[Summary of the invention]

この発明は、電気的消去可能な浮遊ゲート型半導体不渾
発性メモリにおいて、!・ンネル絶縁膜を酸化チッ化膜
を用いることにより、書換え回数の向上をはかったもの
である。
The present invention provides an electrically erasable floating gate semiconductor non-volatile memory. - By using a nitride oxide film as the channel insulating film, the number of rewrites can be increased.

〔従来の技術〕[Conventional technology]

従来、第2図に示すように、基板1の表面のプログラム
端子を韮ねているドレイン領域3の上に約100 人の
シリコン熱酸化膜から成るトンネル酸化膜15を設けた
電気的書換え可能な浮遊ゲート型半導体不揮発性メモリ
が知られていた0例えば、H,S、  Johnson
 et al  ” 16に[i[I’ROM  re
lies ontunneling’for  byt
e−erasable  prog’ram  sLo
raga”ElacLronics、 Februer
y 2B、  1980 ppH3゜に開示されている
Conventionally, as shown in FIG. 2, a tunnel oxide film 15 made of about 100 silicon thermal oxide films is provided on a drain region 3 which serves as a program terminal on the surface of a substrate 1. Floating gate type semiconductor non-volatile memories were known, e.g. H.S. Johnson
et al” 16 [i[I'ROM re
lies ontunneling'for byt
e-erasable prog'ram sLo
raga” ElacLronics, Februer
y 2B, 1980 ppH3°.

〔発明が解決しようとする!!題〕[Invention tries to solve! ! Title]

しかし、従来の半導体不揮発性メモリは、トンネル絶縁
膜として約100 形成度の熱酸化膜が用いられている
ために、ドレイン領域3と浮遊ゲートffl極7との間
で、電荷のやりとり< I!llら、プログラム動作)
をすると、トンネル酸化IK!+5が強電界ストレスに
より偶発的に破壊しやすいという欠点を有していた。
However, in conventional semiconductor non-volatile memories, since a thermal oxide film with a degree of formation of about 100°C is used as a tunnel insulating film, there is no charge exchange between the drain region 3 and the floating gate ffl pole 7 <I! ll et al., program operation)
Then, tunnel oxidation IK! +5 had the disadvantage of being prone to accidental destruction due to strong electric field stress.

そこで、この発明は従来のこのような欠点を解決するた
めに、プログラム動作により偶発破壊しない電気的書換
え可能な半導体不揮発性メモリを得ることを目的として
いる。
SUMMARY OF THE INVENTION In order to solve these conventional drawbacks, it is an object of the present invention to provide an electrically rewritable semiconductor nonvolatile memory that is not accidentally destroyed by programming operations.

〔課題を解決するための手段〕[Means to solve the problem]

L記課題を解決するために、この発明は、トンネル絶縁
膜をCVD法により形成したチノ化シリコン膜を熱酸化
したいわゆる酸化−y−ソ化膜を用いることにより、高
電界ストレスに強(、書換えによる偶発破壊を防止した
In order to solve the problem mentioned above, the present invention uses a so-called oxidized-y-sodide film, which is obtained by thermally oxidizing a tinodized silicon film formed by the CVD method, as a tunnel insulating film, thereby making it resistant to high electric field stress. Prevents accidental destruction due to rewriting.

(実施例) 以下に、この発明の実施例を図面に基づいて説明する。(Example) Embodiments of the present invention will be described below based on the drawings.

N型のメモリの場合について説明する。第1図において
、P型シリコン基板lの表面にお互いに間隔をおいてN
°型のソース領域2とドレイン領域3が形成されている
。ドレイン領域3の上には、部分的にトンネル酸化チッ
化膜が設けられている。また、ソース領域2とドレイン
領域3との間の半導体基4fflの表面であるチャネル
領域の−Lには、酸化膜4が設けられ、さらに、その上
に酸化チッ化膜6が設けられている。浮遊ゲート電極7
は、トンネル酸化チッ化膜5と酸化チッ化膜6の上に設
けられ、さらに、浮遊ゲート電極7の上には、制御ゲー
ト電極9が制御ゲート酸化膜8を介して設けられている
The case of N-type memory will be explained. In FIG. 1, N
° type source region 2 and drain region 3 are formed. A tunnel oxidized nitride film is partially provided on the drain region 3. Further, an oxide film 4 is provided on -L of the channel region, which is the surface of the semiconductor substrate 4ffl between the source region 2 and the drain region 3, and a nitride oxide film 6 is further provided thereon. . floating gate electrode 7
is provided on the tunnel nitride oxide film 5 and the nitride oxide film 6, and furthermore, a control gate electrode 9 is provided on the floating gate electrode 7 with the control gate oxide film 8 interposed therebetween.

本発明のメモリの読み出し動作は、ソース領域2とドレ
イン領域3との間のチャネル領域のコンダクタンスが、
浮遊ゲート電極7に含まれている電?u7PItによっ
て変化することによって行われる。
In the read operation of the memory of the present invention, the conductance of the channel region between the source region 2 and the drain region 3 is
Electricity contained in the floating gate electrode 7? This is done by changing u7PIt.

また、情報のプログラムは、制御ゲート電極9とドレイ
ン領域3との間に高電圧を印加することにより、トンネ
ル酸化チッ化膜5に高電界を集中させトンネル電流をド
レイン領Jjli 3と浮遊ゲート電極7との間に流す
ことにより行うことができる。
In addition, the information is programmed by applying a high voltage between the control gate electrode 9 and the drain region 3, thereby concentrating a high electric field on the tunnel oxide nitride film 5 and directing the tunnel current between the drain region 3 and the floating gate electrode. This can be done by flowing between 7 and 7.

本発明のトンネル絶縁膜である酸化ヂノ化膜の製造方法
について第3図1al〜(dlを用いて説・明する。
A method of manufacturing an oxidized dinide film, which is a tunnel insulating film of the present invention, will be explained using FIGS.

まr、第3図fatに示すように、基板lの全面に酸化
194を形成し、次に、第3図fblのようにトンネル
領域になるiJT域を、フォトリソエIS′により酸化
膜4をエツチッグして基板!まで穴あけする。
First, as shown in FIG. 3 fat, an oxide film 194 is formed on the entire surface of the substrate l, and then, as shown in FIG. And the board! Drill until.

次に100Å以下のCVDシリニlンチソ化膜15を全
面に形成して、第3図(C1のようにする0次に、この
CVDシリコン・I−ソ化膜15を900℃以りの温度
で熱酸化して、その上に、多結晶シリコン薄膜からなる
浮遊ゲート電極7を形成して、第31J +、11のよ
うにする。次に、1000℃以上の高温で浮遊ゲート電
極7を酸化して制御ゲート酸化JI’J8を形成して、
そのJ−に、制御ゲート電極9を形成し、さらに、ソー
ス領域2及びトレイン領域3を)・z遊ゲー1電極7を
マスクにしてドーピングすることにより、第1図の本発
明のメモリが完成する。
Next, a CVD silicon-isolated film 15 with a thickness of 100 Å or less is formed on the entire surface, as shown in FIG. A floating gate electrode 7 made of a polycrystalline silicon thin film is formed thereon by thermal oxidation, as shown in No. 31J+, 11. Next, the floating gate electrode 7 is oxidized at a high temperature of 1000° C. or higher. forming a control gate oxide JI'J8,
A control gate electrode 9 is formed on the J-, and the source region 2 and train region 3 are doped using the ) and z play gate 1 electrodes 7 as masks, thereby completing the memory of the present invention shown in FIG. do.

本発明のトンネル絶縁膜である酸化チッ化膜6は、ノ1
ミ常に酸化速度の遅いCVDシリコン−f・ツ化n21
5を高温で長時間で酸化し°C形成するために、その品
質は、従来のシリコン酸化膜に比べ優れている。その結
果、書換えによるトンネル絶縁膜の破壊が極めて少ない
メモリが実現できる。また、電気的書換え可能な半導体
メモリの場合、プログラム時に、ドレイン領域3、ある
いは、制御ゲート電極8に約10v以上の高電圧を印加
する。この電圧を7シI御する回路が、同−基板上に形
成されている0本発明のメモリにおいては、その高電圧
制御用トランジスタのゲート絶縁1模として、チャネル
領域上の酸化膜4と酸化チッ化膜6との複合膜を用いる
ことにより、ゲート耐圧の高いトランジスタを形成でき
る。
The nitride oxide film 6, which is the tunnel insulating film of the present invention, is
CVD silicon with extremely slow oxidation rate - F/Tsunide n21
5 is oxidized at high temperature for a long time to form the silicon oxide film, its quality is superior to that of conventional silicon oxide films. As a result, a memory in which the tunnel insulating film is extremely less likely to be destroyed by rewriting can be realized. Further, in the case of an electrically rewritable semiconductor memory, a high voltage of about 10 V or more is applied to the drain region 3 or the control gate electrode 8 during programming. In the memory of the present invention in which a circuit for controlling this voltage is formed on the same substrate, an oxide film 4 and an oxide film 4 on the channel region are used as gate insulation 1 of the high voltage control transistor. By using a composite film with the nitride film 6, a transistor with high gate breakdown voltage can be formed.

また、制御ゲート酸化膜8は、tooo℃以上の高温で
、浮遊ゲート電極7の熱酸化により形成する。
Further, the control gate oxide film 8 is formed by thermally oxidizing the floating gate electrode 7 at a high temperature of 0.degree. C. or higher.

この工程は、浮遊ゲート電極7が多結晶シリコンである
ため、その上の膜の品質を保つように高温熱酸化工程で
製造せざるおえない0本発明のメモリでは、トンネル絶
縁膜が酸化チッ化膜であるために、このような高温熱処
理工程があっても、トンネル絶縁膜の品質は劣化しない
、従来は、トンネル絶縁膜が、100人程1のシリコン
酸化膜で形成されていたために、この制御ゲート酸化工
程により品質が(1(下するという問題があった。本発
明のメモリは、制御ゲート電極9を浮遊ゲート電極7の
上に形成した例で説明したが、制御ゲート電極9は、基
板lの表面に形成してもよい。しかし、第1図のような
構造のメモリに、特に通している。
In this process, since the floating gate electrode 7 is made of polycrystalline silicon, it must be manufactured using a high-temperature thermal oxidation process in order to maintain the quality of the film thereon.In the memory of the present invention, the tunnel insulating film is made of nitride oxide. Because it is a film, the quality of the tunnel insulating film does not deteriorate even if it undergoes such a high-temperature heat treatment process. Conventionally, the tunnel insulating film was formed of about 100 silicon oxide films, so this There was a problem that the control gate oxidation process lowered the quality to It may be formed on the surface of the substrate 1. However, it is particularly suitable for a memory having a structure as shown in FIG.

即ら、酸化チッ化膜が高温工程に強いからである。That is, the nitride oxide film is resistant to high temperature processes.

〔発明の効果] この発明は、以上説明したように、トンネル絶縁nりと
して、酸化チッ化nりを用いているために、後工程の制
御ゲート酸化の高温プし1セスによる品質低下をILI
jぎ、書換え回数の向りをする効果がある。
[Effects of the Invention] As explained above, the present invention uses nitride oxide as the tunnel insulator, so the quality deterioration due to one process of high-temperature oxidation of the control gate in the post-process can be avoided.
This has the effect of adjusting the number of rewrites.

【図面の簡単な説明】[Brief explanation of the drawing]

第1図は、この発明にがかる14 ’、、Q体不171
1発性メモリの断面図であり、第2図は、従来の゛1″
、力体不171?発1−1メモリの断面図である。第3
図(al〜(dlは、本発明の半導体率1;1:発性メ
モリの製造〕7 ’lhの1−程順断面図である。 5・・・トンネル酸化チッ化11LA 7・・・浮遊ゲート電極 15・・・トンネル酸化11り 以上 出願人 セイコー電子工業株式会:11代理人 弁理士
  林   敬 之 助牛導1本千il?!+士/土リ
ハlFr面図第1図 従来の−1−簿1本f4纂発イ生〆セリのr1酌図第2
図 +5CVD+・・・1ヒ膜 本発明の半簿体千橿tイ1干゛1の製危万;V工干呈1
゛財10第3図
Figure 1 shows 14', Q physical disability 171 according to this invention
FIG. 2 is a cross-sectional view of a one-shot memory.
, Physical weakness 171? FIG. 1 is a sectional view of a memory 1-1. Third
Figures (al~(dl are semiconductor ratios of 1; 1: production of emissive memory) of the present invention are cross-sectional views of 7' lh in the order of 1-. 5... Tunnel oxidation nitride 11LA 7... Floating Gate electrode 15...Tunnel oxidation 11 or more Applicant Seiko Electronics Co., Ltd.: 11 Agent Patent attorney Takayuki Hayashi 1,000 il?! 1-Book 1 book f4 shearing occurs closing auction r1 cup drawing No. 2
Figure + 5 CVD + ... 1 Film The present invention's half-book body 100% production risk; V process 1
゛Wealth 10 Figure 3

Claims (1)

【特許請求の範囲】[Claims]  第1導電型の半導体基板表面に設けられた第2導電型
のトンネル領域と、前記トンネル領域上に設けられた酸
化チッ化膜から成るトンネル絶縁膜と、前記トンネル絶
縁膜上に設けられた浮遊ゲート電極と、前記浮遊ゲート
電極により制御されるチャネル領域と、前記チャネル領
域上に設けられたゲート絶縁膜とから成り、前記ゲート
絶縁膜がシリコン酸化膜と前記酸化チッ化膜との複合膜
で構成されていることを特徴とする半導体不揮発性メモ
リ。
A tunnel region of a second conductivity type provided on the surface of a semiconductor substrate of a first conductivity type, a tunnel insulating film made of a nitride oxide film provided on the tunnel region, and a floating region provided on the tunnel insulating film. It consists of a gate electrode, a channel region controlled by the floating gate electrode, and a gate insulating film provided on the channel region, and the gate insulating film is a composite film of a silicon oxide film and the nitride oxide film. A semiconductor nonvolatile memory characterized by comprising:
JP13970988A 1988-06-07 1988-06-07 Semiconductor nonvolatile memory Pending JPH01308080A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP13970988A JPH01308080A (en) 1988-06-07 1988-06-07 Semiconductor nonvolatile memory

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP13970988A JPH01308080A (en) 1988-06-07 1988-06-07 Semiconductor nonvolatile memory

Publications (1)

Publication Number Publication Date
JPH01308080A true JPH01308080A (en) 1989-12-12

Family

ID=15251593

Family Applications (1)

Application Number Title Priority Date Filing Date
JP13970988A Pending JPH01308080A (en) 1988-06-07 1988-06-07 Semiconductor nonvolatile memory

Country Status (1)

Country Link
JP (1) JPH01308080A (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6365467B1 (en) 1998-12-30 2002-04-02 Hyundai Electronics Industries Co., Ltd. Method of forming gate oxide layer in semiconductor device

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6365467B1 (en) 1998-12-30 2002-04-02 Hyundai Electronics Industries Co., Ltd. Method of forming gate oxide layer in semiconductor device

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