【摘要】：本文利用射頻反應(yīng)磁控濺射,通過控制濺射過程主要性能參數(shù),系統(tǒng)的研究了襯底溫度、濺射功率、氧分壓以及退火溫度等對氧化鈦薄膜組成、結(jié)構(gòu)及電學性能的影響,并成功研制出一種新型Ti Oy-Ti Ox-Ti Oy(yx)三明治結(jié)構(gòu)多層薄膜壓敏電阻,探討其壓敏特性的來源,并對其性能進行改性研究。結(jié)果表明:(1)在低溫下沉積的薄膜呈現(xiàn)非晶態(tài);隨著襯底溫度的升高,當高達600°C時,薄膜表面顆粒團聚,出現(xiàn)銳鈦礦相。并且隨著襯底溫度的升高而降低;在低溫下制備的薄膜具有電阻變化特性。當氧分壓為零時,隨著濺射功率的升高,Ti Ox薄膜的組成發(fā)生變化,氧元素比例逐漸降低,測試的O/Ti原子比例分別為1.09,1.05,1.06和1.01。隨著濺射功率的升高,薄膜表面顆粒逐漸變大,電阻率也隨之降低。當氧分壓逐漸升高時,薄膜質(zhì)量高,缺陷變少,電阻率逐漸變大。薄膜電阻率隨著退火溫度的提高,先升高后降低。薄膜的載流子遷移率的提高和反應(yīng)過程中產(chǎn)生的吸附態(tài)氧的消除兩因素共同作用,導(dǎo)致薄膜的電阻率減小。Ti Ox和Ti Oy薄膜由于厚度的不同,轉(zhuǎn)折點也不一樣,分別是500-600℃和600-700℃。(2)通過改變?yōu)R射過程中的氧分壓得到了Ti Oy-Ti Ox-Ti Oy(yx)三明治結(jié)構(gòu)薄膜壓敏電阻器。研究發(fā)現(xiàn)這樣的多層薄膜呈現(xiàn)良好的非線性行為,不同于純單層鈦氧化物薄膜的線性行為。獲得的三明治結(jié)構(gòu)的復(fù)合薄膜的壓敏特性行為可以解釋為陷阱和電子的捕獲和釋放。(3)300、400℃的退火后,三明治結(jié)構(gòu)薄膜壓敏電阻器樣品的非線性基本保持不變,漏電流卻變小;而樣品經(jīng)過500℃退火后,非線性急劇變大,漏電流也明顯減小;經(jīng)過600、700℃退火后,樣品沒有表現(xiàn)出非線性,且電阻率較低。本實驗范圍內(nèi)獲得的最佳性能為:非線性系數(shù)為13,壓敏電壓為0.05 V/nm,漏電流0.15 m A/cm2。隨著中間層功率的增大,Ti Oy-Ti Ox-Ti Oy(yx)三明治結(jié)構(gòu)薄膜壓敏電阻器非線性系數(shù)降低、壓敏電壓降低、漏電流增大。本實驗范圍內(nèi)獲得的最佳性能為:非線性系數(shù)為13.4,壓敏電壓為0.93 V/nm,漏電流0.54m A/cm2。
[Abstract]:In this paper, the effects of substrate temperature, sputtering power, oxygen partial pressure and annealing temperature on the composition, structure and electrical properties of titanium oxide films were systematically studied by means of RF reactive magnetron sputtering. A novel multilayer thin film varistor with Ti Oy-Ti Ox-Ti Oy (yx) sandwich structure was successfully developed, the source of its varistor characteristics was discussed, and the properties of the resistor were studied. The results show that: (1) the films deposited at low temperature are amorphous, and with the increase of substrate temperature, when the substrate temperature is as high as 600 擄C, the particles on the surface of the films are agglomerated and anatase phase appears. With the increase of substrate temperature, the films prepared at low temperature have the characteristic of resistance variation. When the oxygen partial pressure is 00:00, the composition of, Ti Ox film changes with the increase of sputtering power, and the proportion of oxygen elements decreases gradually. The measured O/Ti atomic ratios are 1.09U 1.05U 1.06 and 1.01a, respectively. With the increase of sputtering power, the surface particles become larger and the resistivity decrease. When the oxygen partial pressure increases gradually, the film quality is higher, the defect is less, and the resistivity becomes larger. The resistivity of the films increases first and then decreases with the increase of annealing temperature. The increase of carrier mobility of the film and the elimination of the adsorbed oxygen produced in the reaction process result in the decrease of the resistivity of the. Ti Ox film and the reduction of the thickness of the Ti Oy film, and the turning point of the film is different because of the difference in thickness. They are 500-600 鈩，

本文編號：2398578