阅读说明：本技术 氧族硅环戊烷 (Oxosilane cyclopentane ) 是由 B·C·阿克尔斯 R·J·利伯拉托尔 Y·帕恩 于 2020-03-23 设计创作，主要内容包括：描述了一种新的化合物,称为氧族硅环戊烷。这些化合物是含有硅-硒键或硅-碲键的五元环结构,如式(I)和(II)所示。在这些化合物中,硅和环碳上的取代基可以是氢、烷基、烷氧基、芳香族或醚基。氧族硅环戊烷化合物与羟基和其他质子官能团发生开环反应,可用于制备适用于ALD和CVD等薄膜沉积技术的基底。(A novel compound, called oxosilane cyclopentane, is described. These compounds are five-membered ring structures containing a silicon-selenium bond or a silicon-tellurium bond, as shown in formulas (I) and (II). In these compounds, the substituents on the silicon and ring carbons can be hydrogen, alkyl, alkoxy, aromatic or ether groups. The oxosilane cyclopentane compound and hydroxyl and other proton functional groups have ring-opening reaction, and can be used for preparing substrates suitable for ALD, CVD and other thin film deposition technologies.)

1. An oxosilacyclopentane having the structure of formula (I) or (II), wherein R_a、R_b、R_c、R_d、R_e、R_fR and R' are each independently selected from the group consisting of hydrogen, alkyl groups having from 1 to about 8 carbon atoms, alkoxy groups having from 1 to about 8 carbon atoms, aryl groups, and ether groups;

2. the oxosilacyclopentane of claim 1, wherein R is_a、R_b、R_c、R_d、R_e、R_fR and R' are each independently selected from the group consisting of hydrogen, alkyl groups having from 1 to about 8 carbon atoms, and alkoxy groups having from 1 to about 8 carbon atoms.

3. The oxosilacyclopentane of claim 1, having the structure of formula (III):

4. the oxosilacyclopentane of claim 1, having the structure of formula (IV):

5. the oxosilacyclopentane of claim 1, having the structure of formula (V):

6. the oxosilacyclopentane of claim 1, having the structure of formula (VI):

7. the oxosilacyclopentane of claim 1, having a structure selected from the group consisting of:

8. the reaction product of an oxosilacyclopentane as in claim 1, and a protic substance.

9. The reaction product of claim 7 wherein the protic material is a substrate.

10. A method of forming an ALD initiation layer on a proton substrate, comprising reacting a proton substrate with the oxosilacyclopentane of claim 1.

Background

In thin film technology, the surface is often modified to exhibit specific chemical functionalities or to modify the substrate behavior to achieve deposition techniques. The latter is particularly important in technologies requiring ultra-thin conformal layers. For example, Atomic Layer Deposition (ALD) technology is becoming increasingly important in cadmium selenide and cadmium telluride thin film compositions for photovoltaic applications, mercury-cadmium telluride (HgCdTe) deposition for sensor applications, and germanium-antimony-tellurium (GST) deposition for phase change memory and capacitor applications. One common problem observed in these thin film deposition schemes is slow growth during each cycle of the initial stages of ALD, sometimes referred to as incubation or induction during ALD. Generally, this slow growth is related to the reactivity of the substrate, which is of a different composition than the film to be deposited. There remains a need in the art for substrates that can effectively initiate the deposition process.

Disclosure of Invention

Described is an oxosilacyclopentane having the structure of formula (I) or (II) wherein R_a、R_b、R_c、R_d、R_e、R_fR and R' are each independently selected from the group consisting of hydrogen, alkyl groups having from 1 to about 8 carbon atoms, alkoxy groups having from 1 to about 8 carbon atoms, aryl groups, and ether groups;

Detailed Description

The present invention relates to a series of novel heterocyclic silanes, known as oxysilanes. The term "chalcogen" refers to an element of group 16 of the periodic table, and includes selenium (Se) and tellurium (Te). Thus, the invention more particularly relates to selenosilylcyclopentanes and tellurosilacyclopentanes. These compounds undergo the desired ring-opening reaction with hydroxyl and other proton functional groups. Furthermore, surface modification with these materials can make the substrate suitable for thin film deposition techniques such as ALD (atomic layer deposition) and CVD (chemical vapor deposition).

The selenosilentane and tellurosilacyclopentane of the present invention are 5-membered ring structures containing a silicon-selenium bond or a silicon-tellurium bond, as shown in the following compounds having the structures of formulae (I) and (II);

the simplest members of the oxosilacyclopentane of the present invention are not substituted on the ring or on the silicon, i.e., all R' s_aTo R_fAnd R' substituents are both hydrogen atoms, as shown below for compounds having the structures of formulae (III) and (IV):

more generally, the substituents R of the ring carbons_aTo R_fThe substituents R and R' on the silicon atom are each independently hydrogen or an organic group selected from the group consisting of: alkyl and alkoxy groups having 1 to about 8 carbon atoms, more preferably, 4 or less carbon atoms, aromatic groups, and ether groups. More preferably, the substituent is hydrogen, alkyl or alkoxy, more preferably hydrogen, methyl, methoxy or ethoxy. For example, the silicon atom on the oxosilacyclopentane and one atom on the ring carbon are substituted with a methyl group, 2,2, 4-trimethyl-1-selenium-2-silacyclopentane and 2,2, 4-trimethyl-1-tellurium-2-silacyclopentane, as shown in the following formulas (V) and (VI).

Examples of other possible compounds according to the present invention include, but are not limited to, compounds having the following structure:

the oxosilacyclopentane of the present invention can be prepared by reacting 3-chloroisobutyldimethylchlorosilane with lithium oxoxide as shown in scheme I:

the compounds of the present invention can also be prepared by reacting 3-chloroisobutyltrialkoxysilane with lithium alkoxide as shown in scheme II:

similar reactions can be carried out to produce alternative compounds of the invention that do not contain a methyl substituent at the fourth position of the silacyclopentane ring. Such reactions are well understood by those skilled in the art. Alkoxy substituted compounds can be reduced with lithium aluminum hydride or diisobutyl aluminum hydride to produce compounds of the invention having hydrogen substituents on silicon.

The materials of the present invention undergo a ring-opening reaction with a protic substrate, for example containing hydroxyl, thiol and amine groups, generating elements of C-Se-H (selenol) or C-Te-H (tellurol) at a remote position with respect to the substrate. General and specific (e.g., tellurium) ring opening reactions are shown in scheme III and scheme IV.

As described by Harmgarth et al (J. inorganic and general. chem., 2017,1150-1166), for GST films, once tellurium atoms are available as part of the deposition initiation layer, the films can be cleanly grown using various precursors. Thus, substrates prepared from the materials of the present invention are effective for growing clean thin films.

Another interesting comparison between the oxosilacyclopentane and the silacyclopentane is the relative shift of the Si-Me peak in the hydrogen nuclear magnetic spectrum. The most typical shift in the chalcogenide Si-S is associated with the Si-CH moiety. However, the increase in heteroatom size and decrease in electronegativity results in a significant upward field shift of the methyl peak. The shift change indicates that a portion of the positive charge on the silicon atom is stronger, thereby increasing the lewis acidity of the silicon, making the silicon-heteroatom bond more susceptible to heterolysis and thus more reactive toward nucleophiles and proton substrates. In addition, a comparison of the general bond dissociation energies for silicon heteroatom bonds shows that the dissociation energies for Si-Se and Si-Te are similar, whereas the dissociation energy for Si-N is weaker and the dissociation energy for Si-S is stronger. Although these values represent only homolytic cleavage, they are a good indicator of bond strength and the thermodynamic driving force for the ring-opening reaction with hydroxyl and other groups is advantageous.

The invention will now be illustrated in connection with the following non-limiting examples.

Example 1: synthesis of 2,2, 4-trimethyl-1-selenium-2-silacyclopentane

To 500mL of THF was added freshly cleaved lithium metal (13.8g,1.9mol) in a catalytic amount of tolane (8.8g,0.05mol) in 300mL of THF. The addition was slightly exothermic and a reddish brown solution formed. After the exotherm ceased (about 90 minutes), selenium (75g, 0.9mol) was added in small amounts through a powder addition funnel, resulting in a large exotherm. The resulting mixture was heated at reflux for 8 hours to ensure maximum consumption of lithium. Preparation of a mixture containing 175.88g (0.9mol) of 3-chloroisobutyldimethylchlorosilane (commercially available from Gelest) and 1.35g (0.01mol) of BF₃·Et₂O solution and dropwise addition to Li₂In Se, an exotherm results. The reaction was refluxed for 8 hours. All volatiles were removed from the reaction under high vacuum and the resulting mixture was distilled in steps in a fresh apparatus (Vigreux column) to give 2,2, 4-trimethyl-1-selenium-2-silacyclopentane (boiling point: 63-4 ℃/10 mm; density: 1.195 g/m)L)。

The target compound was isolated as a yellow-orange liquid in 28.7% yield. GC-MS and NMR results were consistent with the structure.¹H NMR(CDCl₃,400MHz):δ0.45(s,3H),0.51(s,3H),0.65(dd,1H,J＝11.6,14.0Hz),1.13(d,3H,J＝6.4Hz),1.22(ddd,1H,J＝1.6,4.8,14.0Hz),2.18(m,1H),2.52(t,1H,J＝10Hz),2.89(ddd,1H,J＝2.0,4.8,10.0Hz).

Example 2: synthesis of 2,2, 4-trimethyl-1-tellurium-2-silacyclopentane

Freshly cleaved lithium metal (10.9g,1.6mol) in 200mL of THF was added a catalytic amount of a solution of tolane (7.3g,0.04mol) in an additional 200mL of THF. The addition was slightly exothermic and a reddish brown solution formed. After the exotherm ceased (about 90 minutes), tellurium powder (100g, 0.8mol) was added in small amounts via a powder addition funnel, resulting in a large exotherm. The resulting mixture was heated at reflux for 8 hours to ensure maximum consumption of lithium. Preparation of a mixture containing 145.1g (0.8mol) of chloroisobutyldimethylchlorosilane (commercially available from Gelest) and 1.1g (0.01mol) of BF₃·Et₂O solution and dropwise addition to Li₂In Te, an exotherm results. The reaction was refluxed for 8 hours. All volatiles were removed from the reaction under high vacuum and the resulting mixture was distilled in stages in a fresh unit (Vigreux column) to give 2,2, 4-trimethyl-1-tellurium-2-silacyclopentane (boiling point 61-3 ℃/4). The target compound was isolated as a colorless liquid in 30.3% yield. Upon exposure to light, it begins to appear orange. GCMS and NMR confirmed the structure.¹H NMR(CDCl₃,400MHz):δ0.61(s,3H),0.67(s,3H),0.72(dd,1H,J＝10.8,14.0Hz),1.14(d,3H,J＝6.4Hz),1.34(ddd.1H,J＝1.6,3.6,13.6Hz),2.12(m,1H),2.62(t,1H,J＝10Hz),2.91(ddd,1H,J＝1.6,4.4,10.4Hz)。

It will be appreciated by those skilled in the art that changes could be made to the embodiments described above without departing from the broad inventive concept thereof. In addition, based on the present disclosure, one of ordinary skill in the art will further recognize that the relative proportions of the above-described components can be varied without departing from the spirit and scope of the present invention. It is understood, therefore, that this invention is not limited to the particular embodiments disclosed, but it is intended to cover modifications within the spirit and scope of the present invention as defined by the appended claims.