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  <xsd:element id="acls_ChargesRelatedToReflectLowerOfCostOrMarketValue" name="ChargesRelatedToReflectLowerOfCostOrMarketValue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_LineOfCreditFacilityPortionOfAvailabilityUsedToSupportOutstandingLettersOfCredit" name="LineOfCreditFacilityPortionOfAvailabilityUsedToSupportOutstandingLettersOfCredit" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_EffectiveIncomeTaxRateReconciliationNondeductibleExpenseCreditExpirationsAmount" name="EffectiveIncomeTaxRateReconciliationNondeductibleExpenseCreditExpirationsAmount" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_DepositRelatingToCustomsActivity" name="DepositRelatingToCustomsActivity" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_DeferredTaxAssetsTaxCreditCarryforwardsStateAndLocal" name="DeferredTaxAssetsTaxCreditCarryforwardsStateAndLocal" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" />
  <xsd:element id="acls_SaleAndLeaseBackMember" name="SaleAndLeaseBackMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_BeverlyPropertyOwnerLlcMember" name="BeverlyPropertyOwnerLlcMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_CashCashEquivalentsAndRestrictedCashAbstract" name="CashCashEquivalentsAndRestrictedCashAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_CashCashEquivalentsAndRestrictedCashTextBlock" name="CashCashEquivalentsAndRestrictedCashTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_CashCashEquivalentsAndRestrictedCashTableTextBlock" name="CashCashEquivalentsAndRestrictedCashTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_MoneyMarketFundsUsGovernmentSecuritiesAndAgencyInvestmentsMember" name="MoneyMarketFundsUsGovernmentSecuritiesAndAgencyInvestmentsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_ProvisionForExcessAndObsoleteInventory" name="ProvisionForExcessAndObsoleteInventory" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_ServicesMember" name="ServicesMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_AfterMarketMember" name="AfterMarketMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_PercentageOfPaymentUponShipmentOfTool" name="PercentageOfPaymentUponShipmentOfTool" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_PeriodOfPaymentUponDeliveryOfParts" name="PeriodOfPaymentUponDeliveryOfParts" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_PercentageOfPaymentUponInstallation" name="PercentageOfPaymentUponInstallation" nillable="true" type="dtr-types:percentItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_RevenueFromExternalCustomersByDisciplineAreasTableTextBlock" name="RevenueFromExternalCustomersByDisciplineAreasTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_PeriodOfUnsatisfiedExtendedWarrantyPerformanceObligations" name="PeriodOfUnsatisfiedExtendedWarrantyPerformanceObligations" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_ExtendedProductWarrantyPeriod" name="ExtendedProductWarrantyPeriod" nillable="true" type="xbrli:durationItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_RecognizingAssetsRelatedToRecoverableCustomerContractCostsPolicyTextBlock" name="RecognizingAssetsRelatedToRecoverableCustomerContractCostsPolicyTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_AssetsManufacturedForInternalUseDisclosureTextBlock" name="AssetsManufacturedForInternalUseDisclosureTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_InternalUsedAssetsTypeAxis" name="InternalUsedAssetsTypeAxis" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrldt:dimensionItem" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_InternalUsedAssetsTypeDomain" name="InternalUsedAssetsTypeDomain" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_CompletedInternalUseAssetsMember" name="CompletedInternalUseAssetsMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_NewSystemsRevenueMember" name="NewSystemsRevenueMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_LeaseDisclosureTextBlock" name="LeaseDisclosureTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_OperatingAndFinanceLeaseRightOfUseAsset" name="OperatingAndFinanceLeaseRightOfUseAsset" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" />
  <xsd:element id="acls_OperatingAndFinanceLeaseLiability" name="OperatingAndFinanceLeaseLiability" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_FinanceLeaseAccumulatedDepreciation" name="FinanceLeaseAccumulatedDepreciation" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_FinanceLeaseCost" name="FinanceLeaseCost" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_LeaseBalanceSheetDisclosureTableTextBlock" name="LeaseBalanceSheetDisclosureTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_LeaseCashFlowInformationDisclosureTableTextBlock" name="LeaseCashFlowInformationDisclosureTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_ShortTermAndVariableLeaseCost" name="ShortTermAndVariableLeaseCost" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_LeaseQuantitativeDisclosureTableTextBlock" name="LeaseQuantitativeDisclosureTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_WeightedAverageRemainingLeaseTermAndDiscountRateAbstract" name="WeightedAverageRemainingLeaseTermAndDiscountRateAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_FinanceAndOperatingLeaseLiabilitiesPaymentsDueAbstract" name="FinanceAndOperatingLeaseLiabilitiesPaymentsDueAbstract" nillable="true" type="xbrli:stringItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearTwo" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearTwo" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearThree" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearThree" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFour" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFour" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFive" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueYearFive" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueAfterYearFive" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueAfterYearFive" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDue" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount" name="LesseeOperatingAndFinanceLeaseLiabilityUndiscountedExcessAmount" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_ContractWithCustomerLiabilityDeferralOfRevenue" name="ContractWithCustomerLiabilityDeferralOfRevenue" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_DeferredTaxAssetOperatingLeaseLiabilities" name="DeferredTaxAssetOperatingLeaseLiabilities" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" />
  <xsd:element id="acls_DecreaseInInventoryReserves" name="DecreaseInInventoryReserves" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueNextTwelveMonths" name="LesseeOperatingAndFinanceLeaseLiabilityPaymentsDueNextTwelveMonths" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="credit" />
  <xsd:element id="acls_OperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" name="OperatingAndFinanceLeaseLiabilityMaturityTableTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_ShippingAndHandlingCostsPolicyTextBlock" name="ShippingAndHandlingCostsPolicyTextBlock" nillable="true" type="dtr-types:textBlockItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" />
  <xsd:element id="acls_NetSettlementOnRestrictedStockGrants" name="NetSettlementOnRestrictedStockGrants" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_SiliconValleyBankMember" name="SiliconValleyBankMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_IncomeTaxReconciliationGiltiInclusion" name="IncomeTaxReconciliationGiltiInclusion" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_FederalMember" name="FederalMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_StateMember" name="StateMember" nillable="true" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" abstract="true" xbrli:periodType="duration" />
  <xsd:element id="acls_CostOfPropertyRepairsAndMaintenanceCapitalized" name="CostOfPropertyRepairsAndMaintenanceCapitalized" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" />
  <xsd:element id="acls_DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts" name="DeferredTaxAssetsCapitalizedResearchAndDevelopmentCosts" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="instant" xbrli:balance="debit" />
  <xsd:element id="acls_EffectiveIncomeTaxRateReconciliationPreviouslyUnrecognizedTaxBenefit" name="EffectiveIncomeTaxRateReconciliationPreviouslyUnrecognizedTaxBenefit" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element id="acls_OperatingLossCarryforwardsAreSubjectToUncertainTaxPositionReserve" name="OperatingLossCarryforwardsAreSubjectToUncertainTaxPositionReserve" nillable="true" type="xbrli:monetaryItemType" substitutionGroup="xbrli:item" xbrli:periodType="duration" xbrli:balance="debit" />
  <xsd:element name="PropertyPlantAndEquipmentOtherUsefulLife" id="acls_PropertyPlantAndEquipmentOtherUsefulLife" type="xbrli:durationItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedNumberOfSharesApprovedByShareholders" id="acls_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedNumberOfSharesApprovedByShareholders" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedNumberOfSharesFromExpirationsOrForfeituresOfPriorEquityPlan" id="acls_ShareBasedCompensationArrangementByShareBasedPaymentAwardAuthorizedNumberOfSharesFromExpirationsOrForfeituresOfPriorEquityPlan" type="xbrli:sharesItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="false" />
  <xsd:element name="EmployeeStockPurchasePlan2000And2020Member" id="acls_EmployeeStockPurchasePlan2000And2020Member" type="dtr-types:domainItemType" substitutionGroup="xbrli:item" nillable="true" xbrli:periodType="duration" abstract="true" />
</xsd:schema>
